Image-forming-device management system capable of operating in energy-saving mode

ABSTRACT

An image-forming-device management system includes an image-forming-device, a data communication device and a central management device. A real-time clock circuit (RTC) of the data communication device compares a current time with a predetermined data transmission time. If the current time matches with the data transmission time, the RTC generates a data transmission request that requests for data transmission to the central management device. A CPU included in a part constantly supplied with electricity from a power source in the data communication device instructs a power-source controller to supply the electricity from the power source to a communication-related part including a network control unit (NCU), a modem and an image-forming-device interface, thereby activating the communication-related part. Subsequently, the CPU calls out the central management device by using the NCU, and transmits data acquired from the image-forming-device in advance, to the central management device by using the modem.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a data communication device, animage-forming device such as a copy machine or a facsimile compositedevice, an image-forming-device management system composed of the datacommunication device and the image-forming device, and a method ofcontrolling power supply in the image-forming-device management system.

2. Description of the Related Art

An image-forming-device management system enables each image-formingdevice installed in a large number of customer offices and the like toconnect to a central management device installed in a service center byusing a data communication device and a communication line such as apublic line or an exclusive line. This image-forming device is definedas a copy machine, a printer, a facsimile device, or the like.Additionally, the central management device carries out remotemanagement of the image-forming device through the communication lineand the data communication device (a line adaptor). Such animage-forming-device management system is generally known.

In the above-described image-forming-device management system, theimage-forming device transmits data to the data communication deviceperiodically, for instance, at a certain time every day. Alternatively,the image-forming device transmits the data to the data communicationdevice, in response to a data-transmission requesting signal receivedfrom the data communication device. This data is related to theimage-forming device, and is, for instance, data that indicates a devicestatus including log information such as a total number of formed images(a total counter value) and a surface temperature (a fixing temperature)of a fixing roller inside a fixing unit.

The data communication device stores the data received from theimage-forming device in a memory. The data communication device, then,transmits the data stored in the memory to the central management deviceby calling out spontaneously and periodically, for instance, on a fixeddate and time of every month. Alternatively, the data communicationdevice transmits the data stored in the memory to the central managementdevice, in response to a call signal, in fact, a data-transmissionrequesting signal included in each signal received continuously afterthe call signal, which corresponds to a call out made by the centralmanagement device, and is supplied through the communication line.

Additionally, the data communication device obtains data related to theimage-forming device by transmitting the data-transmission requestingsignal to the image-forming device in accordance with the call signalthat corresponds to the call out made by the central management device,and is received through the communication line, and, then, transmits thedata to the central management device.

In addition, there exists another type of an image-forming-devicemanagement system, in which an image-forming device having a function(communication control means) as a data communication device can beconnected to a central management device installed in a service center,by use of a communication line, and the central management deviceexecutes remote management of the image-forming device through thecommunication line.

In such an image-forming-device management system, the image-formingdevice transmits data related to the image-forming device to the centralmanagement device, by calling out spontaneously and periodically, forinstance, on a fixed date and time of every month, or by responding to acall signal that corresponds to a call out made by the centralmanagement device, and is received through the communication line.

On the other hand, one of recent image-forming devices such as copymachines or facsimile devices has an energy-saving function to stopsupplying power from a power source to a part that consumes muchelectricity, by setting an energy-saving mode, for the purpose of savingenergy or setting consumed energy low if a state in which theimage-forming device is not used for a certain period, or if a fixed keyoperation on an operation display unit is performed.

A facsimile (FAX) device having the above-described energy-savingfunction is shown in FIG. 1, for example. FIG. 1 is a block diagramshowing a structure of a related-art facsimile device that has anenergy-saving function.

This facsimile device includes a CIG4 401, an NCU (Network Control Unit)402, an FCU (Facsimile Control Unit) 403, a scanner 404, a plotter 405and a main control unit 406. In addition, the facsimile device includesan operation display unit, a main power source and a sub power source,which are not shown in the figures.

The CIG4 401 is a unit for a G4 (Group-4 type) of a facsimile device.The NCU 402 is a network control unit that connects or disconnectslines, and detects connected lines. The FCU 403 is a facsimile controlunit that controls communication with an external facsimile device, andincludes a CPU (Central Processing Unit) 411, a ROM (Read Only Memory)412, a RAM (Random Access Memory) 413, an RTC (Real Time Clock) 414, aUART (Universal Asynchronous Receiver/Transmitter) 415, a VIF (VideoInterface) 416, a BUSCNT (Bus Control) 417, a DCR 418, a memory 419, aPORT 420, a FAX modem 421, a COMCNT (Communication Control) 422, an AFE(Analog Front End) 423, a DTMF 424, and the like.

The CPU 411 is a central processing unit that controls the FCU 403entirely. The ROM 412 is a read only memory that stores every type offixed data including a control program used by the CPU 411. The RAM 413is a memory temporarily storing data, and is a work memory used by theCPU 411 for processing data, for instance. The RTC 414 is areal-time-clock circuit that includes a timer function generating acurrent time. The current time is known by the CPU 411 reading thecurrent time generated by the RTC 414.

The UART 415 is a serial communication unit that functions as aninterface exchanging a control signal with the main control unit 406.The VIF 416 is a video interface that exchanges image data (imageinformation) with the main control unit 406. The BUSCNT 417 is a buscontrol circuit that connects or disconnects buses, and substitutes abit on a bus with another bit on the other bus. The DCR 418 is acompression/decompression circuit that compresses or decompresses theimage data. The memory 419 stores the image data. The PORT 420 is an I/O(Input/Output) port that controls input and output of each signal byfollowing an instruction from the CPU 411.

The FAX modem 421 modulates or demodulates image data for a facsimileoperation, which is received or to be transmitted. The COMCNT 422 is acommunication control circuit that controls input and output of eachsignal by following an instruction from the CPU 411. In addition, theCOMCNT 422 detects or receives a call signal (a ringer signal)corresponding to a call out made by an external facsimile device, andnotifies the CPU 411 about the call signal, if the call signal istransmitted from a communication line to the facsimile device shown inFIG. 1. The AFE 423 is an analog front end (an analog signal controlcircuit) that amplifies and filters a signal from the communication line(a telephone line). The DTMF 424 detects a DTMF signal, for example, acombination code of “*#0#” transmitted from an external device to thefacsimile device shown in FIG. 1 through the communication line.

The scanner 404 reads a document image. The plotter 405 forms or printsan image on a sheet of paper, based on image data read by the scanner404, or image data received by the FCU 403 or the like from an externalfacsimile device. The main control unit 406 controls the FCU 403, thescanner 404 and the plotter 405 all together.

The facsimile device structured as described above stops supplying powerto a display device on the operation display unit, the scanner 404 andthe plotter 405 including a fixing roller inside a fixing unit, whoseelectricity consumption amounts are large, by turning the main powersource off in a case in which the energy-saving mode is set.Additionally, the facsimile device continues supplying power from thesub power source to the FCU 403, the CIG4 401 and the NCU 402 thatcompose a control unit.

In a case in which the COMCNT 422 of the FCU 403 receives the callsignal (the ringer signal) that corresponds to the call out made by theexternal facsimile device, and is transmitted from the communicationline through the NCU 402 during the energy-saving mode, the COMCNT 422notifies the CPU 411 about the received call signal. Subsequently, theCPU 411 having received the notification from the COMCNT 422 suppliesthe power to the entire facsimile device by turning the main powersource on. In addition, the CPU 411 outputs image data to the plotter405, and makes the plotter 405 form an image or print the image on asheet of paper, in a case in which the facsimile device receives theimage data from the communication line continuously after the receptionof the call signal.

This facsimile device also stops supplying the power to the display uniton the operation display unit, the scanner 404 and the plotter 405 byturning the main power source off, in a case in which the energy-savingmode is set while a data-transmission time is set (or a time-specifiedtransmission mode is set). However, the facsimile device continuessupplying the power from the sub power source to the FCU 403, the CIG4401 and the NCU 402. In a case in which the CPU 411 determines that thecurrent time generated by the RTC 414 and a predetermineddata-transmission time match with each other by comparing the currenttime and the data-transmission time during the energy-saving mode, theCPU 411 transmits document image data that is read by the scanner 404and is stored in the memory 419 in advance, to a predetermined addressby using the FAX modem 421, the COMCNT 422 and the NCU 402.

However, the initially described image-forming-device management systemusing the data communication device among the above related-artimage-forming-device management systems has the following problems.

The data communication device used in the initially describedimage-forming-device management system keeps turning its main powersource on at all times, thereby being supplied with the power from themain power source constantly, so that the data communication device cantransmit the data related to the image-forming device to the centralmanagement device at any time. Consequently, the image-forming-devicemanagement system wastes electricity when the data communication deviceis not transmitting the data to the central management device.

Additionally, the image-forming device used in the initially describedimage-forming-device management system cannot respond to adata-transmission request transmitted from the data communicationdevice, in a case in which the image-forming device cuts power supplyfrom its main power source to the entire image-forming-device by turningthe main power source off according to a turned-off main switch, or in acase in which the image-forming device cuts the power supply from themain power source to the entire image-forming device by turning the mainpower source off in accordance with continuation of an used state for acertain period, in order to achieve energy saving.

Further, if the main power source of the image-forming device is turnedoff, the data communication device cannot obtain the data related to theimage-forming device therefrom by calling out spontaneously at a fixedtime or by receiving the call signal (the data-transmission requestingsignal) from the central management device, and, thus, cannot transmitthe data to the central management device.

On the other hand, the later described image-forming-device managementsystem whose image-forming device includes the communication controlmeans has the following problems.

The entire image-forming device that has the communication control unit,and is used in the later described image-forming-device managementsystem is supplied with the power from the main power source at alltimes, by turning the main power source on, so that the image-formingdevice can transmit the data about itself to the central managementdevice. Consequently, the image-forming-device management system wasteselectricity when the image-forming device is not transmitting the datato the central management device.

In addition, the image-forming device cannot respond to the call signaltransmitted from the central management device, in a case in which theimage-forming device cuts power supply from its main power source to theentire image-forming device by turning the main power source offaccording to a turned-off main switch, or in a case in which theimage-forming device cuts the power supply from the main power source tothe entire image-forming device by turning the main power source off inaccordance with continuation of an used state for a certain period, inorder to achieve energy saving.

Accordingly, usage of a technology related to the related-art facsimiledevice shown in FIG. 1 may be applied to the image-forming device andthe data communication device used in each image-forming-devicemanagement system described above.

Such a facsimile device stops supplying power to parts consuming muchenergy, such as the display unit on the operation display unit not shownin the figures, the scanner 404 and the plotter 405, by turning the mainpower source off when the energy-saving mode is set. However, thefacsimile device needs to continue supplying the power from the subpower source to the FCU 403, the CIG4 401 and the NCU 402 composing thecontrol unit, so that the facsimile device can transmit or receive imagedata during the energy-saving mode. Thus, the facsimile device certainlyconsumes the electricity for continuing the control unit powered on.

SUMMARY OF THE INVENTION

Accordingly, it is a general object of the present invention to providea data communication device, an image-forming device such as a copymachine, an image-forming-device management system composed of the datacommunication device and the image-forming device, and a method ofcontrolling power supply in the image-forming-device management system.

A more particular object of the present invention is to provide a datacommunication device, an image-forming device such as a copy machine, animage-forming-device management system composed of the datacommunication device and the image-forming device, and a method ofcontrolling power supply in the image-forming-device management system,by which the data communication device or the image-forming device cancarry out data transmission regularly, reducing unnecessary electricityconsumed by the data communication device or the image-forming device.

The above-described object of the present invention is achieved by adata communication device that is connected to a central managementdevice through a communication line, and controls communication betweenthe central management device and an image-forming device, the datacommunication device including a power source; a data-storing unitstoring data related to the image-forming device; a data transmissionunit; a transmission-request generating unit being always supplied withelectricity from the power source, and generating a transmission requestthat requests for transmission of the data to the central managementdevice; and a power-supply control unit being always supplied with theelectricity from the power source, and supplying the electricity fromthe power source to a communication-related part including the datatransmission unit, if the transmission-request generating unit generatesthe transmission request, wherein the data transmission unit transmitsthe data to the control management device if being supplied with theelectricity from the power source.

The above-described object of the present invention is also achieved byan image-forming device that is connected to a data communicationdevice, and communicates with a central management device in accordancewith control carried out by the data communication device, theimage-forming device including a power source; a data transmission unit;and a power-supply control unit being always supplied with electricityfrom the power source, and supplying the electricity from the powersource to a communication-related part including the data transmissionunit if receiving a transmission-request signal from the datacommunication device, wherein the data transmission unit transmits datarelated to the image-forming device, to the data communication device ifbeing supplied with the electricity from the power source.

The above-described object of the present invention is also achieved byan image-forming-device management system, including an image-formingdevice; a data communication device; and a central management devicemanaging the image-forming device remotely through a communication lineand the data communication device, wherein the data communication deviceincludes a first power source; a data-storing unit storing data of theimage-forming device; a data-type deciding-unit; atransmission-request-signal transmitting unit; a first data transmissionunit; a call-origin deciding unit being always supplied with theelectricity from the first power source, and deciding whether a callorigin is the central management device based on a signal receivedcontinuously after a call signal if receiving the call signal from thecommunication line in accordance with a call out made by the callorigin; and a first power-supply control unit being always supplied withthe electricity from the first power source, and supplying theelectricity from the first power source to the data-type deciding unit,the transmission-request-signal transmitting unit and the fist datatransmission unit, if the call-origin deciding unit decides that thecall origin is the central management device, wherein the data-typedeciding unit decides a type of data that should be transmitted to thecentral management device based on the signal received continuouslyafter the call signal from the communication line, if being suppliedwith the electricity from the first power source, wherein thetransmission-request-signal transmitting unit transmits atransmission-request signal to the image-forming device, if and only ifthe transmission-request-signal transmitting unit is supplied with theelectricity from the first power source, and the data-type deciding unitdecides that the data which should be transmitted to the centralmanagement device is the data related to the image-forming device,wherein the first data transmission unit transmits the data related tothe image-forming device to the central management device if beingsupplied with the electricity from the first power source, and receivingthe data related to the image-forming device from the image-formingdevice in response to the transmission-request signal transmitted to theimage-forming device by the transmission-request-signal transmittingunit, and wherein the first power-supply control unit stops supplyingthe electricity from the first power source to the data-type decidingunit, the transmission-request-signal transmitting unit and the firstdata transmission unit, after the first data transmission unit completestransmitting the data related to the image-forming device to the centralmanagement device, wherein the image-forming device includes a secondpower source; a second data transmission unit; and a second power-supplycontrol unit that is always supplied with the electricity from thesecond power source, and supplies the electricity from the second powersource to a communication-related part including the second datatransmission unit if receiving the transmission-request signal from thedata communication device, wherein the second data transmission unittransmits the data related to the image-forming device, to the datacommunication device if being supplied with the electricity from thesecond power source, and wherein the second power-supply control unitstops supplying the electricity from the second power source to thecommunication-related part after the second data transmission unitcompletes transmitting the data related to the image-forming device tothe data communication device.

The above-described object of the present invention is also achieved bya method of controlling power supply in an image-forming-devicemanagement system that remotely manages an image-forming device by usinga central management device through a communication line and a datacommunication device, the method including the steps of supplyingelectricity constantly from a power source of the data communicationdevice to call-signal receiving means for receiving a call signal fromthe communication line according to a call out made by a call origin,and call-origin deciding means for deciding whether the call origin isthe central management device when receiving the call signal by thecall-signal receiving means; supplying the electricity from the powersource of the data communication device to a communication-related partif deciding that the call origin is the central management device by thecall-origin deciding means, the communication-related part includingdata-type deciding means for deciding a type of data that should betransmitted to the central management device based on a signal receivedcontinuously after the call signal from the communication line,transmission-request signal transmitting means for transmitting atransmission request signal added with information indicating the typeof the data that should be transmitted to the central management device,the type being decided by the data-type deciding means, to theimage-forming device if recognizing that the data which should betransmitted to the central management device is data related to theimage-forming device based on a result of deciding the type of the datathat should be transmitted to the central management device, and datatransmission means for receiving data from the image-forming device inresponse to the transmission-request signal transmitted to theimage-forming device, and transmitting the data received from theimage-forming device to the central management device; stopping thepower supply from the power source to the communication-related partafter completing transmission of the data received from theimage-forming device to the central management device; supplying theelectricity constantly from a power source of the image-forming deviceto signal receiving means receiving the transmission-request signal fromthe data communication device; deciding a part that needs the powersupply for acquiring the data which should be transmitted to the centralmanagement device among the data related to the image-forming device,based on the information added to the transmission-request signal if thetransmission-request signal is received by the signal receiving means;supplying the electricity from the power source of the image-formingdevice to the part that needs the power supply for acquiring the datawhich should be transmitted to the central management device, and a partthat needs the power supply for transmitting the data to the datacommunication device; and stopping the power supply from the powersource of the image-forming device to the part that needs the powersupply for acquiring the data which should be transmitted to the centralmanagement device, and the part that needs the power supply fortransmitting the data to the data communication device, aftertransmitting the data to the data communication device.

For instance, a real-time clock circuit (RTC) of the data communicationdevice compares a current time with a predetermined data transmissiontime. If the current time matches with the data transmission time, theRTC generates a data-transmission request that requests for datatransmission to the central management device. A CPU included in a partconstantly supplied with electricity from a power source in the datacommunication device instructs a power-source controller to supply theelectricity from the power source to a communication-related partincluding a network control unit (NCU), a modem and animage-forming-device interface, thereby activating thecommunication-related part. Subsequently, the CPU calls out the centralmanagement device by using the NCU, and transmits data acquired from theimage-forming device in advance, to the central management device byusing the modem.

Accordingly, the data communication device or the image-forming devicecan carry out data transmission regularly, reducing unnecessaryelectricity consumed by the data communication device or theimage-forming device.

Other objects, features and advantages of the present invention willbecome more apparent from the following detailed description when readin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a structure of a related-art facsimiledevice that has an energy-saving function;

FIG. 2 is a block diagram showing a structure of an image-forming-devicemanagement system according to a first embodiment of the presentinvention;

FIG. 3 is a block diagram showing a structure of a control unit of eachimage-forming device used in the image-forming-device management systemaccording to the first embodiment;

FIG. 4 is a block diagram showing a structure of a personal interfaceincluded in the control unit of each image-forming device;

FIG. 5 is a layout diagram showing a structure of an operation displayunit included in each image-forming device;

FIG. 6 is a diagram showing an image-forming (copy) mode screendisplayed on a text-display unit of the operation display unit when thetext-display unit is powered on;

FIG. 7 is a block diagram showing a structure of a data communicationdevice used in the image-forming-device management system according tothe first embodiment;

FIG. 8 is a block diagram showing a structure of an NCU included in thedata communication device;

FIG. 9 is a flowchart showing a selecting operation carried out by thedata communication device;

FIG. 10 is a flowchart showing a polling operation carried out by thedata communication device;

FIG. 11 is a diagram showing a structure of text data transferredbetween a central management device and the data communication device,both being included in the image-forming-device management systemaccording to the first embodiment;

FIG. 12 is a table diagram showing a process code used for communicationbetween the central management device and the data communication device;

FIG. 13 is a table diagram showing a format of an information recordincluded in the text data;

FIG. 14 is a diagram showing a structure of text data transferredbetween the data communication device and the personal interface of theimage-forming device;

FIG. 15 is a diagram showing a structure of text data transferredbetween the personal interface of the image-forming device and a PPCcontroller shown in FIG. 4;

FIG. 16 is a flowchart showing a first example of processes performed bythe data communication device;

FIG. 17 is a flowchart showing a second example of the processesperformed by the data communication device;

FIG. 18 is a flowchart showing a third example of the processesperformed by the data communication device;

FIG. 19 is a flowchart showing a fourth example of the processesperformed by the data communication device;

FIG. 20 is a block diagram showing a structure of a control unit of eachimage-forming device used in an image-forming-device management systemaccording to a second embodiment of the present invention;

FIG. 21 is a block diagram showing a structure of a personal interfacethat is included in the control unit shown in FIG. 20;

FIG. 22 is a block diagram showing a structure of a data communicationdevice used in the image-forming-device management system according tothe second embodiment;

FIG. 23 is a flowchart showing a control process including power-supplycontrol when the data communication device shown in FIG. 22 receives aringer signal;

FIGS. 24A and 24B are flowcharts showing a process carried out by a CPUof the personal interface shown in FIG. 21 during a selecting operation;

FIG. 25 is a diagram showing a communication sequence between thepersonal interface shown in FIG. 21 and the data communication deviceshown in FIG. 22;

FIG. 26 is a flowchart showing a data acquisition process carried out bythe data communication device shown in FIG. 22 in an energy-saving mode;

FIG. 27 is a block diagram showing a structure of units included in eachimage-forming device shown in FIG. 20 and a power-supply circuit;

FIG. 28 is a diagram showing a power-supply mode setting screendisplayed on a text-display unit of an operation display unit includedin each image-forming device shown in FIG. 20;

FIG. 29 is another diagram showing a communication sequence between thepersonal interface shown in FIG. 21 and the data communication deviceshown in FIG. 22;

FIG. 30 is a diagram showing a structure of a fixing-temperaturerequesting signal;

FIG. 31 is a diagram showing power-source control information includedin the fixing-temperature requesting signal shown in FIG. 30;

FIG. 32 is a diagram showing information that indicates an actualrequest for a fixing temperature, and is included in thefixing-temperature requesting signal shown in FIG. 30;

FIG. 33 is a diagram showing a structure of an instruction signal thatincludes the power-source control information shown in FIG. 31, and istransmitted from the data communication device shown in FIG. 22 to eachimage-forming device shown in FIG. 20;

FIG. 34 is a diagram showing image-density change inside a copy sheetwith respect to a change in a value of a current (a drum current) thatflows through a photosensitive drum of each image-forming device shownin FIG. 20;

FIG. 35 is a block diagram showing an example of a connection betweenthe data communication device shown in FIG. 22, and each image-formingdevice shown in FIG. 20;

FIG. 36 is a block diagram showing another example of the connectionbetween the data communication device shown in FIG. 22, and eachimage-forming device shown in FIG. 20;

FIG. 37 is a block diagram showing a structure of a main unit of afacsimile compound device used in an image-forming-device managementsystem according to a third embodiment of the present invention; and

FIG. 38 is a block diagram showing a structure of a main unit of afacsimile compound device used in an image-forming-device managementsystem according to a fourth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description will now be given of preferred embodiments of the presentinvention, with reference to the accompanying drawings.

A description will initially be given of an image-forming-devicemanagement system according to a first embodiment of the presentinvention, with reference to FIG. 2. FIG. 2 is a block diagram showing astructure of the image-forming-device management system according to thefirst embodiment.

The image-forming-device management system according to the firstembodiment includes image-forming devices 1 through 5, a centralmanagement device 6, a data communication device 7 and a communicationline 8.

The image-forming devices 1 through 5 are remotely managed devices suchas copy machines, and are connected to the data communication device 7through a communication line. The data communication device 7 isconnected to the central management device 6 through the communicationline 8 such as a public line or an exclusive line. The centralmanagement device 6 can carry out remote management of the image-formingdevices 1 through 5 collectively through the communication line 8 andthe data communication device 7.

The data communication device 7 is connected to the communication line8, and transmits an instruction signal received from the centralmanagement device 6 to the image-forming devices 1 through 5selectively, or each type of report data received from the image-formingdevices 1 through 5 to the central management device 6 via thecommunication line 8. This instruction signal received from the centralmanagement device 6 is, for instance, a data-transmission requestingsignal that requests for data transmission, or a data-write requestingsignal that requests for a data-write process. The report data is datarelated to the image-forming devices 1 through 5, such as dataindicating a total number of formed images or a device status.

This data communication device 7 is turned on for twenty-four hours aday, and allows communication (data transmission/reception) with thecentral management device 6 even during the night when the image-formingdevices 1 through 5 are normally turned off or cut off. The datacommunication device 7 is connected to the image-forming devices 1through 5 by a multi-drop method using a serial communication interfaceRS-485, and communicates with the image-forming devices 1 through 5 bylater-described polling and selecting operations carried out by the datacommunication device 7.

FIG. 3 is a block diagram showing a structure of a control unit of eachimage-forming device 1 through 5 used in the image-forming-devicemanagement system according to the first embodiment. It should be notedthat the control unit shown in FIG. 3 corresponds to the control unit ofeach image-forming device 1 through 5, in a case in which theimage-forming devices 1 through 5 are copy machines.

The control unit of each image-forming device 1 through 5 includes a PPC(a copy machine) controller composed of a CPU 11, a real-time clockcircuit 12, a ROM 13, a RAM 14, a non-volatile RAM 15, an input/outputport 16, and serial communication control units 17 a, 17 a and 17 c. Thecontrol unit further includes a personal interface or an interface (I/F)18 and a system bus 19.

The CPU 11 is a central processing unit that controls the entire controlunit collectively by using a control program stored in the ROM 13. Thereal-time clock circuit (RTC) 12 includes a time generating unit, atransmission-time setting register and a time comparing unit. The timegenerating unit generates a current time (a year, a month, a date, anhour and a minute). The transmission-time setting register sets adata-transmission time, at which an image-forming device transmits datarelated to the image-forming device, to the central management unit 6 orthe data communication device 7.

In addition, the time comparing unit compares the current time generatedby the time generating unit with the data-transmission time preset inthe transmission-time setting register. The time comparing unitgenerates a data-transmission requesting signal transmitted to thecentral management device 6 or the data communication device 7 if thecurrent time and the data-transmission time match with each other, or ifthe current time passes the data-transmission time.

The ROM 13 is a read only memory that stores various types of fixed dataincluding the control program used by the CPU 11. The RAM 14 is atemporarily storing memory such as a work memory used by the CPU 11processing data, for example. The non-volatile RAM 15 is a memory thatstores data indicating contents of a mode instruction supplied from aunit such as a laterdescribed operation display unit shown in FIG. 5,for example, and can store the data even if the image-forming device isturned off.

The input/output port 16 connects output loads such as a motor, asolenoid and a clutch included in the image-forming device, sensors, andswitches. The serial communication control unit 17 a exchanges a signalwith the operation display unit. The serial communication control unit17 a exchanges a signal with a document transmission unit not shown inthe figures. Additionally, the serial communication control unit 17 cexchanges a signal with a copy sheet or sheet after-processing unit notshown in the figures.

The personal interface 18 is an interface circuit that managescommunication between the image-forming device and the datacommunication device 7, and is provided for reducing a load of the CPU11 for carrying out a communication process between the image-formingdevice and the data communication device 7. If a processing ability ofthe CPU 11 is high enough to manage the communication between theimage-forming device and the data communication device 7, the CPU 11 mayinclude functions of the personal interface 18.

The functions of the personal interface 18 are to monitor polling andselecting operations from the data communication device 7; to transmitan affirmative response or a negative response to the data communicationdevice 7; to check fairness of data transmitted to or received from thedata communication device 7, check parity and request forre-transmission of the data in a case in which an error occurs; and tocarry out a header process of data transmitted to or received from thedata communication device 7.

The system bus 19 is a bus line composed of an address bus, a controlbus and a data bus, and connects the CPU 11, the real-time clock circuit12, the ROM 13, the RAM 14, the non-volatile RAM 15, the input/outputport 16, the serial communication control units 17 a, 17 a and 17 c, andthe personal interface 18 to each other. FIG. 4 is a block diagramshowing a structure of the personal interface 18 included in the controlunit of each image-forming device 1 through 5.

The personal interface 18 shown in FIG. 4 includes a CPU 21, a dual-portmemory 22, registers 23 through 26, an input port 27, a serialcommunication control unit 28, a local bus 29 and a device-code settingswitch 30. The CPU 21 is a microcomputer fabricated on a single chipincluding a central processing unit, a ROM, a RAM, a bus connecting eachunit, and the like, and controls the entire personal interface 18collectively. The dual-port memory 22 is a data memory that can be reador written by both of the CPU 21 and the CPU 11 shown in FIG. 3, and isused for transferring text data between the personal interface 18 and aPPC controller 31. This PPC controller 31 is composed of the CPU 11, thereal-time clock circuit 12, the ROM 13, the RAM 14, the non-volatile RAM15, the input/output port 16, and the serial communication control units17 a, 17 a and 17 c, which are described above.

The registers 23 through 26 are used for controlling the transfer of theabove-described text data, and their detailed descriptions are omittedin this embodiment. The device-code setting switch 30 sets a fixeddevice code for each image-forming device, and is used for identifying adevice code when the data communication device 7 carries out the pollingand selecting operations. The serial communication control unit 28 isconnected to the data communication device 7 and/or the personalinterfaces 18 of other image-forming devices.

FIG. 5 is a layout diagram showing a structure of the operation displayunit included in each image-forming device 1 through 5. This operationdisplay unit corresponds to the operation display unit of eachimage-forming device 1 through 5 if each image-forming device is a copymachine.

Alike a general control unit such as the control unit of eachimage-forming device 1 through 5 shown in FIG. 3, the operation displayunit includes a ROM storing a control program, a CPU executing variouscontrol processes by using the control program, a RAM temporarilystoring data, a non-volatile RAM storing data even if the operationdisplay unit is turned off, a serial communication control unit, aninput/output port, and the like. This operation display unit and theserial communication control unit 17 a shown in FIG. 3 carry out datatransfer to each other, but its description is omitted in the firstembodiment.

The operation display unit shown in FIG. 5 includes a ten key 71, aclear/stop key 72, a print key 73, an enter key 74, an interruption key75, a pre-heat/mode-clear key 76, a mode confirmation key 77, a screenswitch key 78, a call key 79, a registration key 80, a guidance key 81,a display-contrast volume 82 and a text-display unit 83, in addition tothe above-described control unit.

The ten key 71 is a key used for inputting numerical values such as thenumber of copies or image formation, and a scale factor. The clear/stopkey 72 is a key used for clearing the numerical values such as thenumber of copies, and for stopping a copying operation. The print key 73is a key used for starting the copying operation that includes aprinting operation (an image forming operation). The enter key 74 is akey used for confirming settings of numerical values such as a zoomingfactor and a binding-margin dimension size number. The interruption key75 is a key used for copying a document by interrupting a copyingprocess of another document.

The pre-heat/mode-clear key 76 is a key used for canceling all the setcontents of a copy mode, and for setting the image-forming device to anelectricity-saving state (the energy-saving mode). The mode confirmationkey 77 is a key used for confirming each copy mode displayed selectivelyon the text-display unit 83, by displaying a list of each copy mode. Thescreen switch key 78 is a key used for switching a displaying form ofthe text-display unit 83 according to a mastery level of a user. Thecall key 79 is a key used for calling a user program. The registrationkey 80 is a key used for registering the user program. The guidance key81 is a key used for displaying a guidance message or-the like on thetext-display unit 83. The display-contrast volume 82 is used foradjusting contrast of the text-display unit 83.

The text-display unit 83 uses a full-dot display device such as an LCD(Liquid Crystal Display) or a fluorescent character display tube, andlays an almost transparent and sheet-shaped matrix touch panel on a topof the full-dot display device. This matrix touch panel includes aplurality of touch sensors, each touch sensor being located on each 8×8display pixels, for instance. When the operation display unit issupplied with the electricity by turning the main power source on, thetext-display unit 83 can display a normal copy mode screen indicating astatus of the image-forming device, the number of copies, and variouskeys, as shown in FIG. 6. The status of the image-forming device may bedisplayed on the text-display unit 83 as “ready to copy”, “copying”, “nocopy paper”, or the like.

A user can select various copy modes related to the copying operationsuch as a paper-supply tray (a sheet size), an automatic sheet mode, animage density (a copy density), an automatic density mode, achanging-scale mode, a both-sides mode, a binding-margin mode, a sortmode or the like, by touching keys on the copy mode screen. A keytouched by the user turns its color over from black to white, or fromwhite to black. If the user selects the automatic sheet mode, apaper-supply tray storing the most appropriate copy paper isautomatically selected by the image-forming device according to a sizeof a document and a set scale factor. In addition, if the user selectsthe automatic density mode, an image density is selected automaticallyby the image-forming device according to a density (a gray scale) of thedocument. The changing-scale mode includes an equal size mode, areduction mode, an expansion mode, a changing-scale mode by specifying asheet size, a zooming mode, and a changing-scale mode by changing ameasurement.

FIG. 7 is a block diagram showing a structure of the data communicationdevice 7 that is shown in FIG. 2, and is used in theimage-forming-device management system according to the firstembodiment. The data communication device 7 shown in FIG. 7 includes aCPU 41, a ROM 42, a RAM 43, an RTC (Real-Time Clock circuit) 44, animage-forming-device interface (I/F) 45, an NCU 46, a modem 47, apower-supply controller 48, and the like.

The CPU 41 is a central processing unit that controls the entire datacommunication device 7 collectively. In detail, the CPU 41 controlscommunication between the data communication device 7 and a plurality ofthe image-forming devices 1 through 5 by following a control programstored in the ROM 42, and controls transmission/reception of aninstruction signal to the central management device 6 via thecommunication line 8. In addition, the CPU 41 calls the centralmanagement device 6 via the communication line 8 based on each type ofreport data received from the image-forming devices 1 through 5, andcontrols switching to connect the communication line 8 to a side of theimage-forming devices 1 through 5, or to connect to a side of a generaltelephone device (TEL) or a facsimile device (FAX).

The ROM 42 is a read only memory that stores various types of fixed dataincluding the control program used by the CPU 41. The RAM 43 is a randomaccess memory (data storing means) used as a work memory for the CPU 41processing data, or a data memory for storing later-described variousdata (parameters). This RAM 43 stores transmission data transmitted fromone of the central management device 6 and the plurality ofimage-forming devices 1 through 5 to the other, and various parameterssuch as a device code and an ID code specifying one of the plurality ofimage-forming devices 1 through 5, a data-transmission time (a year, amonth, a date, an hour and a minute), a telephone number (a calldestination) of the central management device 6, the number of re-calls(retries) in a case in which a line connection is not succeeded, and aninterval between re-calls.

The RTC 44 has a function as data-transmission request generating meansincluding time generating means. In detail, the RTC 44 includes a timegenerating unit, a transmission-time setting register and a timecomparing unit. The time generating unit generates a current time (ayear, a month, a date, an hour and a minute). The transmission-timesetting register sets a data-transmission time, at which the datacommunication device 7 transmits data related to one of theimage-forming devices 1 through 5, to the central management device 6.

In addition, the time comparing unit compares the current time generatedby the time generating unit with the data-transmission time preset inthe transmission-time setting register. The time comparing unitgenerates a data-transmission requesting signal transmitted to thecentral management device 6 if the current time and thedata-transmission time match with each other, or if the current timepasses the data-transmission time.

The image-forming-device interface 45 is an interface circuit thatmanages serial communication between the data communication device 7 andthe image-forming devices 1 through 5. The NCU 46 connects the datacommunication device 7 to the communication line 8 so that the datacommunication device 7 can communicate with the other devices, andincludes an automatic call originating/terminating function. This NCU 46functions as data transmission means with the CPU 41 and the modem 47.The modem 47 modulates or demodulates data to be transmitted orreceived.

It should be noted that the CPU 41, the ROM 42, the RAM 43 and the RTC44 are set as a power-supply system A, and the image-forming-deviceinterface 45, the NCU 46 and the modem 47 are set as a power-supplysystem 3B. The data communication device 7 is supplied with electricityfrom an AC adaptor 49.

The AC adaptor 49 converts AC 100V of a commercial power-supply systemto DC 15V. The power-supply controller 48 has a function asmain-power-source/power-supply control means. In detail, thepower-supply controller 48 converts DC 15V supplied from the AC adaptor49 to 5V used in the data communication device 7, and supplies thevoltage 5V to the power-supply systems A and B.

It should be noted that the data communication device 7 has anenergy-saving mode and a normal operation mode, for instance. The datacommunication device 7 can shift to the normal operation mode in a casein which the data communication device 7 communicates with the centralmanagement device 6 and the image-forming devices 1 through 5, orcarries out internal processes. Else, the data communication device canshift to the energy-saving mode.

The power-supply systems A and B are electrically independent from eachother in terms of power supply. The power-supply system A is suppliedwith electricity from the power-supply controller 48 at all times. Onthe other hand, the power-supply system B is not supplied withelectricity from the power-supply controller 48 if an operation mode ofthe data communication device 7 is the energy-saving mode. The datacommunication device 7 shifts from the energy-saving mode to the normaloperation mode, or from the normal operation mode to the energy-savingmode, by controlling power supply to the power-supply systems A and Baccording to an instruction from the CPU 41.

FIG. 8 is a block diagram showing a structure of the NCU 46 included inthe data communication device 7. The NCU 46 shown in FIG. 8 includes aprotection circuit 51, a loop-current detecting circuit 52, a ringingdetecting circuit 53, a line switching circuit 54, a loop formingcircuit 55 and the like. The protection circuit 51 is a circuit thatprotects the data communication device 7 from a noise received throughthe communication line 8. The loop-current detecting circuit 52 detectsa current flowing through a direct current (DC) loop formed by the loopforming circuit 55, and includes a bi-directional photo coupler notshown in the figures, and the like.

The ringing detecting circuit 53 detects a call signal (a ringing) fromthe communication line 8. The line switching circuit 54 switchesconnecting the communication line 8 to a side of the modem 47 shown inFIG. 7, or a side of a general telephone device (TEL) or a facsimiledevice (FAX). The loop forming circuit 55 forms the direct current loopwhen catching the communication line 8 or connecting lines L1 and L2 ofthe communication line 8 directly by off-hook, and transmits a modemsignal (a voice-grade signal) to, or receives the modem signal from thecommunication line 8.

A description will now be given of summarized functions of theimage-forming-device management system according to the firstembodiment. The image-forming-device management system has mainly threetypes of functions, which are communication control (1) from the centralmanagement device 6 to the image-forming devices 1 through 5,communication control (2) from the image-forming devices 1 through 5 tothe central management device 6 or the data communication device 7, andcontrol (3) of the data communication device 7 itself.

The communication control (1) from the central management device 6 tothe image-forming device 1 through 5 is the followings (A1, A2 and A3),for example.

(A1) The communication control (1) from the central management device 6to the image-forming devices 1 through 5 is, for instance, to read andreset counter information (text data) such as a total number of formingimages, the number of forming images for each paper-supply tray, thenumber of forming images for each copy paper size, the number ofmis-feedings, the number of mis-feedings for each copy paper size, thenumber of mis-feedings for each copy-paper carrying position and thelike at a specific image-forming device.

(A2) In addition, the communication control (1) from the centralmanagement device 6 to the image-forming devices 1 through 5 is to set(write) and read adjusting values (log information) such as a controlvoltage, a current, a resistance, a fixing temperature and a timing ofeach unit composing the specific image-forming device.

(A3) Further, the communication control (1) from the central managementdevice 6 to the image-forming devices 1 though 5 is to return a result(text data) from the central management device 6 to the image-formingdevices 1 through 5 in response to the communication control (2) fromthe image-forming devices 1 through 5, to the central management device6.

The data communication device 7 carries out the above-describedcommunication controls by receiving an instruction signal from thecentral management device 6 and performing a selecting operation to theimage-forming devices 1 through 5. This selecting operation is to selectone of the five image-forming devices 1 through 5 connected to the datacommunication device 7, and to communicate with a selected image-formingdevice.

FIG. 9 is a flowchart showing the selecting operation carried out by thedata communication device 7.

Each image-forming device 1 through 5 has a unique or specific devicecode. The CPU 41 of the data communication device 7 outputs a specificcode (a combination of codes) indicating a predetermined selectingfunction and a device code of an image-forming device that is to beselected, to the serial communication interface RS-485, in a case inwhich the data communication device 7 receives an instruction signalfrom the central management device 6 through the communication line 8after receiving a call signal from the communication line 8 by using theNCU 46 and the modem 47 in the normal operation mode. The specific codeindicating the selecting function and the device code compose aselecting signal (SA). The normal operation mode can be selected by aswitch operation not shown in the figures.

In a case in which the CPU 11 of each image-forming device 1 through 5is supplied with electricity from the main power source, the CPU 11compares the device code that follows the specific code (the combinationof codes) indicating the selecting function, with a device code of itsown image-forming device, by using the specific code, if receiving theselecting signal (SA) from the data communication device 7 by use of thepersonal interface 18. If the device code of the image-forming devicematches with the device code that is included in the selecting signalsupplied from data communication device 7, the image-forming devicerecognizes that the image-forming device is selected by the datacommunication device 7.

In a case in which the selected image-forming device has data to beoutputted, the CPU 11 of the selected image-forming device transmits a“busy” response indicated by a predetermined specific code (acombination of codes) to the data communication device 7 by using thepersonal interface 18. When the data communication device 7 receives the“busy” response from the image-forming device by using theimage-forming-device interface 45 at a step Si shown in FIG. 9, the CPU41 of the data communication device 7 interrupts the selectingoperation, and shifts to a later-described polling operation.

On the other hand, if the selected image-forming device does not havedata to be outputted, the CPU 11 of the image-forming device decideswhether the image-forming device can correspond to the selectingoperation carried out by the data communication device 7. If it isdetermined that the image-forming device can correspond to the selectingoperation, the CPU 11 transmits an affirmative response indicated by apredetermined specific code (a combination of codes) to the datacommunication device 7 by using the personal interface 18, and carriesout communication between the image-forming device and the datacommunication device 7.

If the data communication device 7 receives the affirmative responsefrom the image-forming device at a step S2 shown in FIG. 9, the datacommunication device 7 transmits a signal (text data) to theimage-forming device, at a step S3. If the data communication device 7finishes the selecting operation at a step S4, the data communicationdevice proceeds to the polling operation. If not, the data communicationdevice proceeds to the step S2.

If the image-forming device receives a data-transmission requestingsignal from the data communication device 7 by using the personalinterface 18 at the step S3, the CPU 11 of the image-forming devicetransmits data that is related to the image-forming device and indicatesa device status such as the above-described counter information and thelog information, to the data communication device 7, by using thepersonal interface 18. If the image-forming device receives a data-writerequesting signal from the data communication device 7 by using thepersonal interface 18 at the step S3, the CPU 11 of the image-formingdevice writes data such as log information or parameters attached to thedata-write requesting signal, to the non-volatile RAM 15.

If it is determined that the image-forming device cannot correspond tothe selecting operation carried out by the data communication device 7,the CPU 11 of the image-forming device transmits a negative responseindicated by a predetermined specific code (a combination of codes) tothe data communication device 7 by using the personal interface 18, andterminates communication between the image-forming device and the datacommunication device 7. When the data communication device 7 receivesthe negative response from the image-forming device at a step S5 shownin FIG. 9, the data communication device 7 proceeds to the pollingoperation.

Further, in a case in which an image-forming device corresponding to thedevice code outputted by the data communication device 7 cannot transmitneither of the affirmative response nor the negative response to thedata communication device 7 since the image-forming device is turnedoff, for example, the data communication device 7 finishes the selectingoperation after a predetermined period passes (step S6 shown in FIG. 9).

A description will now be given of one of the three main functions ofthe image-forming-device management system, which is the communicationcontrol (2) from the image-forming devices 1 through 5 to the centralmanagement device 6 or the data communication device 7. Examples of thiscommunication control (2) are described below (B1 through B5).

(B1) In a case in which a failure occurs so that an image-formingoperation is disabled at each image-forming device 1 through 5, the CPU11 of each image-forming device 1 through 5 transmits data indicatingthe failure (emergency-call data) by using the personal interface 18immediately to the data communication device 7, where the datacommunication device 7 transmits the data indicating the failure (anemergency report) to the central management device 6 through thecommunication line 8.

(B2) The CPU 11 of each image-forming device 1 through 5 shifts from animage forming mode to a user-request input mode used by a user to inputa necessary request such as a repair request or an equipment-supplyrequest, in response to a key operation carried out by the user on theoperation display unit. The CPU 11, then, displays a user-request inputscreen on the text-display unit 83 of the operation display unit. Whenthe necessary request is inputted, by the user pressing down a fixed keyon the screen, the CPU 11 transmits data indicating the necessaryrequest (emergency-call data) by using the personal interface 18immediately to the data communication device 7, where the datacommunication device 7 transmits the data (an emergency report) to thecentral management device 6 through the communication line 8.

(B3) The CPU 11 of each image-forming device 1 through 5 transmits dataindicating a total number of forming images or an order of copy paper(emergency-call data) immediately to the data communication device 7 byusing the personal interface 18 every time the total number of formingimages reaches a predetermined number (a reporting-level value), wherethe data communication device 7 transmits the data (an emergency report)to the central management device 6 through the communication line 8.

(B4) The CPU 11 of each image-forming device 1 through 5 transmits dataindicating the total number of forming images to the data communicationdevice 7 by using the personal interface 18 for every predeterminedperiod. At a preset data-transmission time on a specific day, the CPU 41of the data communication device 7 transmits the data received from theimage-forming device before the data-transmission time together as anon-emergency report, by using the NCU 46 and the modem 47, to thecentral management device 6 through the communication line 8. Thiscommunication control includes control to transmit the data to thecentral management device 6 without waiting for the presetdata-transmission time, in a case in which the number of transmittingthe data reaches a predetermined number before the data-transmissiontime. It should be noted that the data-transmission time is set by thecentral management device 6, and is stored in the RAM 43 inside the datacommunication device 7.

(B5) The CPU 11 of each image-forming device 1 through 5 transmits dataindicating that preventive maintenance is necessary, to the datacommunication device 7 by using the personal interface 18, in a case inwhich the image-forming operation can be started, but an event thatneeds preventive maintenance occurs. This event is, for instance, anevent in which the number or the period which exchangeable parts areused for becomes closer to a predetermined number of times or apredetermined period, or an event in which a sensor reaches a standardlevel. At a preset data-transmission time on a specific day, the CPU 41of the data communication device 7 transmits the data (a no-nemergencyreport) received from the image-forming device before thedata-transmission time together, by using the NCU 46 and the modem 47,to the central management device 6 through the communication line 8.This communication control includes control to transmit the data to thecentral management device 6 without waiting for the data-transmissiontime, in a case in which the number of transmitting the data receivedfrom image-forming device reaches a predetermined number. It should benoted that the data-transmission time is set by the central managementdevice 6, and is stored in the RAM 43 inside the data communicationdevice 7.

The above-described communication controls (B1 through B5) are performedwhen the data communication device 7 carries out the polling operation.The polling operation is to specify an order (1 through 5) of the fiveimage-forming devices connected to the data communication device 7, andto confirm existence and non-existence of a communication request (adata-transmission request) from a specified image-forming device.

FIG. 10 is a flowchart showing the polling operation carried out by thedata communication device 7. The CPU 41 of the data communication device7 outputs a predetermined specific code (a combination of codes)indicating a polling function, and a device code of an image-formingdevice that is to be selected, to the serial communication interfaceRS-485 by using the image-forming-device interface 45 in the normaloperation mode. The specific code indicating the polling function andthe device code compose a polling signal (PA) together.

The CPU 11 of each image-forming device 1 through 5 compares the devicecode that follows the specific code (the combination of codes)indicating the polling function, with a device code of its ownimage-forming device, by using the specific code, if receiving thepolling signal (PA) from the data communication device 7 by use of thepersonal interface 18. If the device code of the image-forming devicematches with the device code that is included in the polling signalsupplied from data communication device 7, the image-forming devicerecognizes that the image-forming device is polled by the datacommunication device 7.

Subsequently, the CPU 11 of an image-forming device polled by the datacommunication device 7 starts communication with the data communicationdevice 7, or transmission of data related to the image-forming device,if the image-forming device has output data or receives adata-transmission request requesting transmission of data to the datacommunication device 7 or the central management device 6. On the otherhand, if the image-forming device does not have the output data, or thepreviously-started communication has ended, the CPU 11 of theimage-forming device transmits an end response indicated by apredetermined specific code (a combination of codes) to the datacommunication device 7 by using the personal interface 18, and, then,terminates the communication between the image-forming device and thedata communication device 7. If the data communication device 7 receivesthe end response from the image-forming device by using theimage-forming-device interface 45 at a step S7 shown in FIG. 10, the CPU41 of the data communication device 7 shifts to the polling operationperformed to the next image-forming device.

In addition, in a case in which an image-forming device corresponding tothe device code outputted by the data communication device 7 cannotstart the communication with the data communication device 7 or cannoteven output the end response since the image-forming device is turnedoff, the CPU 41 of the data communication device 7 finishes the pollingoperation after a predetermined period passes (a step S9 shown in FIG.10). This polling operation is repeated sequentially by the datacommunication device 7 to each image-forming device 1 through 5connected to the data communication device 7 in the normal operationmode unless the data communication device 7 performs the selectingoperation.

A description will now be given of one of the three main functions ofthe image-forming-device management system, which is the control (3) ofthe data communication device 7 itself. This control (3) includes thefollowing controls C1 and C2.

(C1) The control C1 is to read data related to an image-forming devicesuch as a total counter value (a total number of forming images).

(C2) The control C2 is to return a result of communication from theimage-forming devices 1 through 5 to the data communication device 7according to the communication control (2).

The data communication device 7 controls reading the data related to theimage-forming device such as the total counter value, by carrying outthe selecting operation when a data-acquisition request from theimage-forming device is generated. The data-acquisition request from theimage-forming device is assumed to be generated at a predetermined dataacquisition time, for example, at 0:00 AM once a day. In a case in whichthe image-forming device is turned off when the data-acquisition requestis generated, the data communication device 7 controls reading the totalcounter value by the selecting operation performed when theimage-forming device is turned on for the first time after theimage-forming device is turned off. Additionally, if the operation modeof the data communication device 7 is the energy-saving mode when thedata-acquisition request is generated, the CPU 41 of the datacommunication device 7 supplies electricity to the power-supply system Bby use of the power-supply controller 48, and controls to activate theimage-forming-device interface 45.

The data communication device 7 has two memories for a total counter ofeach image-forming device connected to the data communication device 7,in the RAM 43, which are named a memory A and a memory B. The CPU 41writes the total counter value read by the selecting operation once aday as described above, in the memory A. Thus, every day, the totalcounter value written in the memory A on the previous day is rewrittenover by the total counter value of the present day. However, if thepresent day is a holiday on which an image-forming device is not turnedon all day long, the total counter value of the previous day is notrewritten by the total counter value of the present day. Additionally,the CPU 41 copies the total counter value stored in the memory A to thememory B on a predetermined day of each month, which is set by thecentral management device 6 and stored in the RAM 43 of the datacommunication device 7.

The data communication device 7 transmits contents (the total countervalue) of the memory B to the central management device 6 by followingone of methods D1 and D2 described below.

(D1) The central management device 6 reads the total counter valuestored in the memory B of the data communication device 7 after contentsof the memory A is copied to the memory B. In detail, the centralmanagement device 6 connects itself to the data communication device 7by calling the data communication device 7, so that the centralmanagement device 6 can communicate with the data communication device7. Subsequently, the central management device 6 accesses to the datacommunication device 7 by transmitting a corresponding data-transmissionrequesting signal (a reading instruction) to the data communicationdevice 7, and obtains the contents (the total counter value of eachimage-forming device 1 through 5) of the memory B, which is transmittedfrom the data communication device 7.

(D2) The CPU 41 of the data communication device 7 calls spontaneouslyby use of the NCU 46 at a predetermined data-transmission time (a year,a month, a date, an hour and a minute), that is, after theabove-described date on which the contents of the memory A is copied tothe memory B, and, then, transmits the total counter value stored in thememory B to the central management device 6 through the communicationline 8 by using the NCU 46 and the modem 47. If the operation mode ofthe data communication device 7 is the energy-saving mode, the datacommunication device 7 needs to carry out later-described power-supplycontrol. The data-transmission time is set by the central managementdevice 6, and is stored in the RAM 43 of the data communication device7.

It should be noted that the data communication device 7 includes aplurality of memories (recording areas), each being composed of thememories A and B, in the RAM 43 for each image-forming device connectedto the data communication device 7, because various total counter valuesmay be assigned for black/white copy, application copy and color copy,for instance.

FIG. 11 is a diagram showing a structure of text data transferredbetween the central management device 6 and the data communicationdevice 7. A “numbers” shown in FIG. 11 is a communication block numberin one data transmission. The first block in the data transmission has acommunication block number “0”. Then, the communication block number isincremented by one, up to “99”. A communication block number followingthe communication block number “99” becomes “00”.

An ID code is used for specifying the data communication device 7 andone of the five image-forming devices 1 through 5 that are connected tothe data communication device 7. A distinguishing code is a process codethat indicates a type of a communication purpose including a type ofdata to be transmitted to the central management device 6, added with anorigin (a transmitting end) and a destination (a receiving end) of thetext data. The above-described process code is predetermined as shown inFIG. 12. In FIG. 12, a process code “02” corresponds to thedata-transmission requesting signal that requests data transmission(data read). Additionally, a process code “04” corresponds to thedata-write requesting signal that requests writing data.

An information record shown in FIG. 11 has an information code, a datapart and a digit number of the data part, which are determined as shownin FIG. 13. A semicolon is inserted as a separator between the ID codeand the distinguishing code, between the distinguishing code and theinformation record, and between the information records.

FIG. 14 is a diagram showing text data transferred between the datacommunication device 7 and the personal interface 18 of theimage-forming devices 1 through 5. A device code shown in FIG. 14 is setindividually by the device-code setting switch 30 shown in FIG. 4 foreach image-forming device 1 through 5. A relation between this devicecode and the ID code shown in FIG. 11 is read from an image-formingdevice when the image-forming device is installed and connected to thedata communication device 7 for the first time, and, then, is stored inthe RAM 43 of the data communication device 7. Since then, the relationbetween the device code and the ID code is changed according to adirection of transmitting the text data. A process code shown in FIG. 14is a code indicating a type of a communication purpose, as describedabove, and equals to the distinguishing code shown in FIG. 11 withoutthe origin and the destination of the text data. This process code isadded or discarded by the data communication device 7 according to adirection of transmitting the text data.

FIG. 15 is a diagram showing a structure of text data transferredbetween the personal interface 18 of the image-forming device 1 through5 and the PPC controller 31 shown in FIG. 4. The text data shown in FIG.15 eliminates a header, the device code and a parity part from the textdata that is shown in FIG. 14, and is transferred between the datacommunication device 7 and the personal interface 18.

A description will now be given of processes performed by the datacommunication device 7 used in the image-forming-device managementsystem according to the first embodiment, with reference to FIGS. 16through 19.

FIG. 16 is a flowchart showing a first example of the processesperformed by the data communication device 7. The data communicationdevice 7 is assumed being in the energy-saving mode. In such anenergy-saving mode, the power-supply controller 48 supplies electricityto only the power-supply system A. In other words, the power-supplycontroller 48 supplies the electricity to only the CPU 41, the ROM 42,the RAM 43 and the RTC 44.

The time comparing unit included in the RTC 44 generates adata-transmission request for the central management device 6 to the CPU41, or interrupts the CPU 41, when reaching the predetermineddata-transmission time (a call time). Examples of a data-transmissionrequest generating process by the time comparing unit of the RTC 44 areshown below (E1, E2, E3 and E4).

(E1) The time comparing unit compares the current time generated by thetime generating unit with the data-transmission time preset in thetransmission-time setting register, and generates the data-transmissionrequest that requests for data transmission to the central managementdevice 6, if the current time matches with the data-transmission time,or if the current time passes the data-transmission time.

Alternatively, the RTC 44 may include only the time generating unit as aclock function. The transmission-time setting register and the timecomparing unit may be provided separately from the RTC 44. In such acase, the RAM 43 may secure an area therein for the transmission-timesetting register, for instance. Accordingly, the time comparing unitcompares the current time generated by the RTC 44 with thedata-transmission time preset in the transmission-time setting register,and generates the data-transmission request that requests for datatransmission to the central management device 6, if the current timematches with the data-transmission time, or if the current time passesthe data-transmission time.

(E2) The time comparing unit compares the current time generated by thetime generating unit with the data-transmission time preset in thetransmission-time setting register, and decides whether the RAM 43 (datastoring means) stores data related to an image-forming device, if thecurrent time matches with the data-transmission time, or if the currenttime passes the data-transmission time. If the time comparing unitdecides that the RAM 43 stores the data related to the image-formingdevice, the time comparing unit generates the data-transmission requestthat requests for data transmission to the central management device 6.

Alternatively, the RTC 44 may include only the time generating unit as aclock function. The transmission-time setting register and the timecomparing unit may be provided separately from the RTC 44. In such acase, the RAM 43 may secure an area therein for the transmission-timesetting register, for instance. Accordingly, the time comparing unitcompares the current time generated by the RTC 44 with thedata-transmission time preset in the transmission-time setting register,and notifies the CPU 41 about correspondence of the current time and thedata-transmission time if the current time matches with thedata-transmission time, or if the current time passes thedata-transmission time. When the CPU 41 receives the notification fromthe time comparing unit, the CPU 41 decides whether the RAM 43 (datastoring means) stores data related to an image-forming device. If theCPU 41 decides that the RAM 43 stores the data related to theimage-forming device, the CPU 41 generates the data-transmission requestthat requests for data transmission to the central management device 6.

(E3) The time comparing unit decides whether the RAM 43 stores the datarelated to the image-forming device. If the time comparing unit decidesthat the RAM 43 stores the data related to the image-forming device, thetime comparing unit compares the current time generated by the timegenerating unit, with a data-transmission time that is preset in thetransmission-time setting register and corresponds to the data. The timecomparing unit generates the data-transmission request that requests fordata transmission to the central management device 6, if the currenttime matches with the data-transmission time, or if the current timepasses the data-transmission time.

Alternatively, the RTC 44 may include only the time generating unit as aclock function. The transmission-time setting register and the timecomparing unit may be provided separately from the RTC 44. In such acase, the RAM 43 may secure an area therein for the transmission-timesetting register, for instance. Accordingly, the CPU 41 decides whetherthe RAM 43 stores the data related to the image-forming device. If theCPU 41 decides that the RAM 43 stores the data related to theimage-forming device, the CPU 41 notifies the time comparing unit aboutthe existence of the data in the RAM 43. After receiving thenotification from the CPU 41, the time comparing unit compares thecurrent time generated by the RTC 44, with the data-transmission timepreset in the transmission-time setting register. The time comparingunit generates the data-transmission request that requests for datatransmission to the central management device 6, if the current timematches with the data-transmission time, or if the current time passesthe data-transmission time.

(E4) The time comparing unit decides whether the RAM 43 stores the datarelated to the image-forming device. If the time comparing unit decidesthat the RAM 43 stores the data related to the image-forming device, thetime comparing unit sets a data-transmission time to the centralmanagement device 6, in a transmission-time setting registercorresponding to the data. Subsequently, the time comparing unitcompares the data-transmission time set in the transmission-time settingregister, with the current time generated by the time generating unit.The time comparing unit generates the data-transmission request thatrequests for data transmission to the central management device 6, ifthe current time matches with the data-transmission time, or if thecurrent time passes the data-transmission time.

Alternatively, the RTC 44 may include only the time generating unit as aclock function. The transmission-time setting register and the timecomparing unit may be provided separately from the RTC 44. In such acase, the RAM 43 may secure an area therein for the transmission-timesetting register, for instance. Accordingly, the CPU 41 decides whetherthe RAM 43 stores the data related to the image-forming device. If theCPU 41 decides that the RAM 43 stores the data related to theimage-forming device, the CPU 41 sets a data-transmission time to thecentral management device 6, in a transmission-time setting registercorresponding to the data. Subsequently, the time comparing unitcompares the current time generated by the RTC 44, with thedata-transmission time set in the transmission-time setting register.The time comparing unit generates the data-transmission request thatrequests for data transmission to the central management device 6, ifthe current time matches with the data-transmission time, or if thecurrent time passes the data-transmission time.

The CPU 41 of the data communication device 7 starts the processes shownin FIG. 16 periodically. In a case in which the CPU 41 generates thedata-transmission request from the RTC 44 to the central managementdevice 6 at a step S11 shown in FIG. 16, the CPU 41 instructs thepower-supply controller 48 to supply electricity to the power-supplysystem B by turning on the main power source. In a case in which thepower-supply controller 48 receives the instruction from the CPU 41, thepower-supply controller 48 supplies electricity to the entire datacommunication device 7 at a step S12, by supplying electricity to thepower-supply system B, which is a part related to communication, andincludes the NCU 46 and the modem 47 functioning as data transmissionmeans. Consequently, the power-supply controller 48 activates the NCU46, the modem 47 and the image-forming-device interface 45, which areincluded in the power-supply system B. Thus, the data communicationdevice 7 shifts from the energy-saving mode to the normal operationmode.

Subsequently, the CPU 41 instructs the NCU 46 to call the centralmanagement device 6. The CPU 41, then, reads out data that is related toan image-forming device, and is obtained from one of the image-formingdevice 1 though 5, from the RAM 43, and transmits the data to thecentral management device 6 through the communication line 8 by usingthe NCU 46 and the modem 47, at a step S13. In detail, the CPU 41instructs the modem 47 to modulate the data read out from the RAM 43,and instructs the NCU 46 to transmit the data modulated by the modem 47,to the central management device 6 through the communication line 8.

A large number of recent CPUs have an energy-saving mode, and may beused as the CPU 41 of the data communication device. In detail, when thedata communication device 7 is in the energy-saving mode, the CPU 41 ofthe data communication device 7 becomes also in the energy-saving mode.At this moment, the CPU 41 may start up periodically by its clockfunction, and may obtain the current time from the RTC 44. Subsequently,the CPU 41 may compare the current time with a data-transmission timestored or preset inside the CPU 41.

The CPU 41 is included in the power-supply system A of the datacommunication device 7, which is always supplied with electricity. Whenthe data-transmission request that requests for data transmission to thecentral management device 6 is generated, the CPU 41 starts supplyingelectricity from the power-supply controller 48 to the power-supplysystem B, which includes the NCU 46 and the modem 47 functioning as thedata transmission means. The CPU 41, then, transmits the data related tothe image-forming devices 1 through 5, to the central management device6, by using the NCU 46 and the modem 47 activated by the power supply.As described above, the data communication device 7 is supplied withelectricity at least when the data communication device 7 carries outdata transmission (automatic report) to the central management device 6.On the other hand, electricity is supplied to only functions thatsatisfies minimum requirement of the data communication device 7 in theenergy-saving mode. Accordingly, the data communication device 7 canachieve reduction of unnecessary power consumption.

Additionally, according to the data-transmission request generatingprocess as described in E1 through E4, means that needs power supplyconstantly for generating the data-transmission request that requestsfor data transmission to the central management device 6 can be composedof minimum requirement, that is, the RTC 44. Thus, the datacommunication device 7 can further reduce power consumption.

FIG. 17 is a flowchart showing a second example of the processesperformed by the data communication device 7. The data communicationdevice 7 is assumed being in the energy-saving mode. In this state,electricity is supplied from the power-supply controller 48 to only thepower-supply system A, which includes the CPU 41, the ROM 42, the RAM 43and the RTC 44. The time comparing unit inside the RTC 44 generates thedata-transmission request for the central management device 6 to the CPU41, when reaching the predetermined data-transmission time, as describedabove. Details of this data-transmission request generating process aredescribed above.

The CPU 41 starts the processes shown in FIG. 17 periodically. When theCPU 41 generates the data-transmission request from the RTC 44 to thecentral management device 6 at a step S21 shown in FIG. 17, the CPU 41instructs the power-supply controller 48 to supply electricity to thepower-supply system B by turning the main power source. In a case inwhich the power-supply controller 48 receives the instruction from theCPU 41, the power-supply controller 48 switches to supply electricity tothe entire data communication device 7 at a step S22, by supplyingelectricity to the power-supply system B, which is the part related tocommunication, and includes the NCU 46 and the modem 47 functioning asthe data transmission means. Consequently, the power-supply controller48 activates the NCU 46, the modem 47 and the image-forming-deviceinterface 45, which are included in the power-supply system B. Thus, thedata communication device 7 shifts from the energy-saving mode to thenormal operation mode.

Subsequently, the CPU 41 instructs the NCU 46 to call the centralmanagement device 6. The CPU 41, then, reads out data that is related toan image-forming device, and is obtained from the image-forming devices1 though 5, from the RAM 43, and transmits the data to the centralmanagement device 6 through the communication line 8 by using the NCU 46and the modem 47, at a step S23.

After completing transmission of the data related to the image-formingdevice, the CPU 41 instructs the power-supply controller 48 to stopsupplying the electricity to the power-supply system B. If receiving theinstruction to stop the power-supply to the power-supply system B fromthe CPU 41, the power-supply controller 48 stops supplying theelectricity to the power-supply system B by turning off the main powersource to the power-supply system B, and deactivates the NCU 46, themodem 47 and the image-forming-device interface 45, at a step S24.Consequently, the data communication device 7 shifts back from thenormal operation mode to the energy-saving mode. It should be noted thatthe energy-saving mode of the CPU 41 can be utilized in this secondexample.

The CPU 41 is included in the power-supply system A of the datacommunication device 7, which is always supplied with electricity. Whenthe data-transmission request that requests for data transmission to thecentral management device 6 is generated, the CPU 41 starts supplyingelectricity from the power-supply controller 48 to the power-supplysystem B related to communication, which includes the NCU 46 and themodem 47 functioning as the data transmission means. The CPU 41, then,transmits the data related to the image-forming devices 1 through 5, tothe central management device 6, by using the NCU 46 and the modem 47activated by the power supply. After completing the transmission of thedata to the central management device 6, the CPU 41 stops supplying theelectricity from the power-supply controller 48 to the power-supplysystem B, which is the, part related to communication.

As described above, the data communication device 7 is supplied withelectricity entirely only when the data communication device 7 carriesout data transmission to the central management device 6. On the otherhand, electricity is supplied to only functions that satisfies minimumrequirement of the data communication device 7 in the energy-savingmode. Accordingly, the data communication device 7 can achieve reductionof unnecessary power consumption.

FIG. 18 is a flowchart showing a third example of the processesperformed by the data communication device 7. The data communicationdevice 7 is assumed being in the energy-saving mode. In this state,electricity is supplied from the power-supply controller 48 to only thepower-supply system A. In other words, the electricity is supplied tothe CPU 41, the ROM 42, the RAM 43 and the RTC 44. The time comparingunit inside the RTC 44 generates the data-transmission request for thecentral management device 6 to the CPU 41, when reaching thepredetermined data-transmission time, as described above.

The CPU 41 starts the processes shown in FIG. 18 periodically. When theCPU 41 generates the data-transmission request from the RTC 44 to thecentral management device 6 at a step S31 shown in FIG. 18, the CPU 41instructs the power-supply controller 48 to supply electricity to thepower-supply system B by turning the main power source.

In a case in which the power-supply controller 48 receives theinstruction from the CPU 41, the power-supply controller 48 switches tosupply electricity to the entire data communication device 7 at a stepS32, by supplying electricity to the power-supply system B, which is thepart related to communication, and includes the NCU 46 and the modem 47functioning as the data transmission means. Consequently, thepower-supply controller 48 activates the NCU 46, the modem 47 and theimage-forming-device interface 45, which are included in thepower-supply system B. Thus, the data communication device 7 shifts fromthe energy-saving mode to the normal operation mode.

Subsequently, the CPU 41 instructs the NCU 46 to call the centralmanagement device 6. The CPU 41, then, reads out data that is related toan image-forming device, and is obtained from the image-forming devices1 though 5, from the RAM 43, and transmits the data to the centralmanagement device 6 through the communication line 8 by using the NCU 46and the modem 47, at a step S33.

After the CPU 41 completes transmission of the data related to theimage-forming device, and a predetermined fixed period passes after thecompletion of the transmission at a step S34, the CPU 41 instructs thepower-supply controller 48 to stop supplying the electricity to thepower-supply system B. For instance, the CPU 41 sets the above-describedfixed period, for example, three minutes, to an internal timer, andinstructs the power-supply controller 48 to stop supplying theelectricity to the power-supply system B when the internal timertimeouts or has counted the fixed period.

If receiving the instruction to stop the power-supply to thepower-supply system B from the CPU 41, the power-supply controller 48stops supplying the electricity to the power-supply system B by turningoff the main power source to the power-supply system B, and deactivatesthe NCU 46, the modem 47 and the image-forming-device interface 45, at astep S35. Consequently, the data communication device 7 shifts back fromthe normal operation mode to the energy-saving mode.

The data communication device 7 is not in the energy-saving mode beforethe above-described fixed period passes, or before the internal timertimeouts. Thus, the CPU 41 can receive an instruction signal from thecentral management device 6 by using the NCU 46 and the modem 47, andtransmits a response to the central management device 6 by using the NCU46 and the modem 47. Consequently, the data communication device 7 cancommunicate with the central management device 6 before the fixed periodpasses. It should be noted that the energy-saving mode of the CPU 41 canalso be utilized in this third example, as described above.

The CPU 41 is included in the power-supply system A of the datacommunication device 7, which is always supplied with electricity. Whenthe data-transmission request that requests for data transmission to thecentral management device 6 is generated, the CPU 41 starts supplyingelectricity from the power-supply controller 48 to the power-supplysystem B related to communication, which includes the NCU 46 and themodem 47 functioning as the data transmission means. The CPU 41, then,transmits the data related to the image-forming devices 1 through 5, tothe central management device 6, by using the NCU 46 and the modem 47activated by the power supply.

After the CPU 41 completes the transmission of the data to the centralmanagement device 6, and the fixed period passes after the transmissionof the data, the CPU 41 stops supplying the electricity from thepower-supply controller 48 to the power-supply system B, which is thepart related to communication. Accordingly, the image-forming-devicemanagement system according to the first embodiment can obtain thefollowing effects.

The data communication device 7 is supplied with electricity entirelyonly when the data communication device 7 carries out data transmissionto the central management device 6. On the other hand, electricity issupplied to only functions that satisfies minimum requirement of thedata communication device 7 in the energy-saving mode. Accordingly, thedata communication device 7 can achieve reduction of unnecessary powerconsumption.

Additionally, the data communication device 7 can communicate with thecentral management device 6, in the fixed period between the completionof transmitting the data related to the image-forming-device, and thediscontinuation of supplying the electricity to the power-supply systemB, which is the part related to communication. For example, the datacommunication device 7 can change a part or all of various parametersthat include the above-described fixed time and period, and are storedin the RAM 43, by receiving the instruction signal from the centralmanagement device 6, in the fixed period. Consequently, theimage-forming-device management system can increase its processingefficiency, and can be structured as a general-purpose system.

FIG. 19 is a flowchart showing a fourth example of the processesperformed by the data communication device 7. The data communicationdevice 7 is assumed being in the energy-saving mode. In this state,electricity is supplied from the power-supply controller 48 to only thepower-supply system A. In other words, the electricity is supplied tothe CPU 41, the ROM 42, the RAM 43 and the RTC 44. The time comparingunit inside the RTC 44 generates the data-transmission request for thecentral management device 6 to the CPU 41, when reaching thepredetermined data-transmission time, as described above.

The CPU 41 starts the processes shown in FIG. 19 periodically. When theCPU 41 generates the data-transmission request from the RTC 44 to thecentral management device 6 at a step S41 shown in FIG. 19, the CPU 41instructs the power-supply controller 48 to supply electricity to thepower-supply system B by turning the main power source on.

In a case in which the power-supply controller 48 receives theinstruction from the CPU 41, the power-supply controller 48 switches tosupply electricity to the entire data communication device 7 at a stepS42, by supplying electricity to the power-supply system B, which is thepart related to communication, and includes the NCU 46 and the modem 47functioning as the data transmission means. Consequently, thepower-supply controller 48 activates the NCU 46, the modem 47 and theimage-forming-device interface 45, which are included in thepower-supply system B. Thus, the data communication device 7 shifts fromthe energy-saving mode to the normal operation mode.

Subsequently, the CPU 41 instructs the NCU 46 to call the centralmanagement device 6. The CPU 41, then, reads out data that is related toan image-forming device, and is obtained from the-image-forming devices1 though 5, from the RAM 43, and transmits the data to the centralmanagement device 6 through the communication line 8 by using the NCU 46and the modem 47, at a step S43.

After the CPU 41 completes transmission of the data related to theimage-forming device, and a predetermined fixed period passes after thecompletion of the transmission at a step S44, the CPU 41 instructs thepower-supply controller 48 to stop supplying the electricity to thepower-supply system B. For instance, the CPU 41 sets the above-describedfixed period, for example, three minutes, to an internal timer, andinstructs the power-supply controller 48 to stop supplying theelectricity to the power-supply system B when the internal timertimeouts or has counted the fixed period.

If receiving the instruction to stop the power-supply to thepower-supply system B from the CPU 41, the power-supply controller 48stops supplying the electricity to the power-supply system B by turningoff the main power source to the power-supply system B, and deactivatesthe NCU 46, the modem 47 and the image-forming-device interface 45, at astep S47. Consequently, the data communication device 7 shifts back fromthe normal operation mode to the energy-saving mode.

The data communication device 7 is not in the energy-saving mode beforethe above-described fixed period passes, or before the internal timertimeouts. Thus, the CPU 41 allows reception of an instruction signalfrom the central management device 6 while the above-described fixedperiod does not pass. If the data communication device 7 receives data(parameters) used for changing parameters, as the instruction signal,from the central management device 6 by using the NCU 46 and the modem47 at a step S45, the CPU 41 of the data communication device 7 changesa part or all of various parameters stored in the RAM 43 by using thedata at a step S46, and instructs the power-supply controller 48 to stopsupplying the electricity to the power-supply system B.

The various parameters stored in the RAM 43 includes data indicating thecall time (the data-transmission time) at which the data communicationdevice 7 calls the central management device 6, and data indicating thefixed period taken from the transmission of the data related to theimage-forming devices 1 through 5 to the central management device 6, tothe shift from the normal operation mode to the energy-saving mode. Itshould be-noted that the energy-saving mode of the CPU 41 may beutilized in this fourth example.

The CPU 41 is included in the power-supply system A of the datacommunication device 7, which is always supplied with electricity. Whenthe data-transmission request that requests for data transmission to thecentral management device 6 is generated, the CPU 41 starts supplyingelectricity from the power-supply controller 48 to the power-supplysystem B related to communication, which includes the NCU 46 and themodem 47 functioning as the data transmission means. The CPU 41, then,transmits the data related to the image-forming devices 1 through 5, tothe central management device 6, by using the NCU 46 and the modem 47activated by the power supply.

After the CPU 41 completes the transmission of the data to the centralmanagement device 6, and the fixed period passes after the transmissionof the data, the CPU 41 stops supplying the electricity from thepower-supply controller 48 to the power-supply system B, which is thepart related to communication. Accordingly, the image-forming-devicemanagement system according to the first embodiment can obtain thefollowing effects.

The data communication device 7 is supplied with electricity entirelyonly when the data communication device 7 carries out data transmissionto the central management device 6. On the other hand, electricity issupplied to only functions that satisfies minimum requirement of thedata communication device 7 in the energy-saving mode. Accordingly, thedata communication device 7 can achieve reduction of unnecessary powerconsumption.

Additionally, the data communication device 7 allows the reception ofthe instruction signal from the central management device 6 until thefixed period passes after the completion of the above-described datatransmission, or during the fixed period before stopping the powersupply to the part related to communication by use of the power-supplycontroller 48. Thus, the data communication device 7 can easily change apart or all of the various parameters stored in the RAM 43 by receivingthe instruction signal. Consequently, the image-forming-devicemanagement system can certainly increase its processing efficiency, andcan be structured as a general-purpose system.

A description will now be given of an image-forming-device managementsystem according to a second embodiment of the present invention. Asshown in FIG. 2, the image-forming-device management system according tothe second embodiment includes the image-forming devices 1 through 5,the central management device 6, the data communication device 7 and thecommunication line 8.

The image-forming devices 1 through 5 are remotely managed devices, andare connected to the data communication device 7. The data communicationdevice 7 is connected to the central management device 6 through thecommunication line 8. The central management device 6 can carry outremote management of the image-forming devices 1 through 5 collectivelythrough the communication line 8 and the data communication device 7.Structures of the image-forming devices 1 through 5 and the datacommunication device 7, and operations performed by the image-formingdevices 1 through 5 and the data communication device 7 according to thesecond embodiment are different from those of the image-forming devices1 through 5 and the data communication device 7 according to the firstembodiment. Thus, a detailed description will be given of parts of thesecond embodiment that are different from the first embodiment. On theother band, common parts between the first embodiment and the secondembodiment will be described simply.

FIG. 20 is a block diagram showing a structure of a control unit of eachimage-forming device 1 through 5 used in the image-forming-devicemanagement system according to the second embodiment. A unit shown inFIG. 20 corresponding to a unit shown in FIG. 3 has the same unit numberas the unit shown in FIG. 3.

The control unit of each image-forming device 1 through 5 includes thePPC controller composed of the CPU 11, the RTC (Real-Time Clock circuit)12, the ROM 13, the RAM 14, the non-volatile RAM 15, the input/outputport 16, and the serial communication control units 17 a, 17 a and 17 c.The control unit further includes the personal interface 18, the systembus 19, a main power source 61, a sub power source 62 and a backupswitch 63.

The CPU 11 is a central processing unit that controls the entire controlunit collectively by using a control program stored in the ROM 13, andfunctions as power-supply part setting means. The real-time clockcircuit (RTC) 12 functions as data-transmission request generating meansincluding time generating means, and includes a time generating unit, atransmission-time setting register and a time comparing unit. The timegenerating unit generates a current time (a year, a month, a date, anhour and a minute). The transmission-time setting register sets adata-transmission time, at which an image-forming device transmits datarelated to the image-forming device, to the central management unit 6 orthe data communication device 7.

In addition, the time comparing unit compares the current time generatedby the time generating unit with the data-transmission time preset inthe transmission-time setting register. The time comparing unitgenerates a data-transmission requesting signal (a data-transmissionrequest) transmitted to the central management device 6 or the datacommunication device 7 if the current time and the data-transmissiontime match with each other, or if the current time passes thedata-transmission time.

This RTC 12 is supplied with electricity constantly from the sub powersource 62 separated from the main power source 61, and, thus, cangenerate the accurate current time even if the main power source 61 isturned off.

The personal interface 18 shown in FIG. 20 has functions as datatransmission means, power-supply control means and startup-signaltransmission means with the CPU 11 and the like, in addition to the samefunction as the personal interface 18 shown in FIG. 3. This personalinterface 18 shown in FIG. 20 is supplied with electricity from the subpower source 62 constantly, and, thus, can monitor an output of the datacommunication device 7 even if the main power source is turned off.Accordingly, the personal interface 18 can receive each signal includinga selecting signal and a polling signal, from the data communicationdevice 7.

The main power source 61 supplies electricity to the entireimage-forming device when a main switch not shown in the figures isturned on. Additionally, the main power source 61 supplies electricityto a part that is related to communication, and includes the CPU 11functioning as the data transmission means, and a part that needs powersupply to obtain data to be transmitted to the central management device6, when the main power source 61 receives a main-power-source turning-onsignal (a startup signal) as a main-power-source control signal from thepersonal interface 18.

On the other hand, the main power source 61 receives a main-power-sourceturning-off signal from the CPU 11, and is turned off, thereby stoppingthe power supply to each part, after the image-forming device finishesdata transmission to the data communication device 7, or after theimage-forming device finishes an image forming operation, and, then, apredetermined fixed time, for example, an hour, passes while theimage-forming device is unused. Further, the main power source 61 isturned off, when the main switch is turned off.

The sub power source 62 is a low-power power source different from themain power source 61. The sub power source 62 supplies electricity tothe personal interface 18 and the main power source 61 to activate eachstartup circuit of the personal interface 18 and the main power source61, or to turn on the personal interface 18 and the main power source61, if the backup switch 63 is turned on. Thus, the personal interface18 and the main power source 61 are supplied with the electricitycontinuously from the sub power source 62, unless the backup switch isturned off.

FIG. 21 is a block diagram showing a structure of the personal interface18 that is included in the control unit shown in FIG. 20. The personalinterface 18 shown in FIG. 21 has the same hardware structure andfunctions as the personal interface 18 shown in FIG. 4. In addition, thepersonal interface 18 shown in FIG. 21 has the following function. TheCPU 21 turns on the main power source 61 by using the main-power-sourcecontrol signal if the CPU 21 receives the selecting signal that composesthe data-transmission requesting signal or the data-write requestingsignal, from the data communication device 7 by using the serialcommunication control unit 28. The other functions of the image-formingdevices 1 though 5 according to the second embodiment are the same asthose of the image-forming devices 1 through 5 according to the firstembodiment, and, thus, their descriptions are omitted.

FIG. 22 is a block diagram showing a structure of the data communicationdevice 7 used in the image-forming-device management system according tothe second embodiment. The data communication device 7 shown in FIG. 22includes a battery 101, a CPU 102, a non-volatile RAM 103, an RTC(Real-Time Clock circuit) 104, a call-time control unit 105, a ROM 106,a serial communication control unit 107, a network control unit (NCU)108, a modem 109, an I/O (Input/Output) control unit 110, a power-sourcecontrol unit 111, a main power source 112, and the like.

The battery 101 is a power source different from the main power source112, and always supplies electricity to the non-volatile RAM 103, theRTC 104, the call-time control unit 105, the NCU 108 and thepower-source control unit 111. The battery 101 may be a rechargeablebattery. Alternatively, a sub power source or a high-capacity condensercan be substituted for the battery 101.

The CPU 102 is a central processing unit that controls the entire datacommunication device 7 collectively. In detail, the CPU 102 controls aplurality of the image-forming devices 1 through 5, andtransmission/reception of an instruction signal to the centralmanagement device 6 via the communication line 8, by following a controlprogram stored in the ROM 106. Additionally, the CPU 102 calls out thecentral management device 6 via the communication line 8 based onvarious report data received from the image-forming devices 1 through 5,by following the control program. This CPU 102 functions as data writingmeans and the power-supply part setting means.

The non-volatile RAM 103 is a readable and writable memory (data storingmeans) defined as a work memory used by the CPU 102 when processing dataor a data memory storing later-described various data. This non-volatileRAM 103 is always supplied with the electricity from the battery 101,and, thus, can store data even if the main power source 112 is turnedoff. The non-volatile RAM 103 may be a memory, which does not need powersupply from the battery 101.

The non-volatile RAM 103 stores transmission data transmitted from oneof the central management device 6 and the plurality of theimage-forming devices 1 through 5 to the other, a device code (adistinguishing number) and an ID code specifying one of the plurality ofthe image-forming devices 1 through 5, a data-transmission time (a year,a month, a date, an hour and a minute), a data acquisition time (a year,a month, a date, an hour and a minute), a telephone number of thecentral management device 6, the number of recalls or retries in a casein which line connection is not successful, transmission processinformation (parameters) such as a recall interval, and a job number ofthe transmission process information.

The RTC 104 functions as the time generating means, and generates acurrent time (a year, a month, a date, an hour and a minute). This RTC104 is always supplied with the electricity from the battery 101, and,thus, can generate the accurate current time even if the main powersource 112 is turned off. The call-time control unit 105 functions asdata-transmission request generating means and data-acquisition requestgenerating means with the RTC 104, and includes a transmission-timesetting register, an acquisition-time setting register and a timecomparing unit. The transmission-time setting register sets adata-transmission time to transmit data related to the image-formingdevices 1 through 5 to the central management device 6. Theacquisition-time setting register sets a data-acquisition time toacquire data from the image-forming devices 1 through 5.

The time comparing unit of the call-time control unit 105 compares thecurrent time generated by the RTC 104 with the data-transmission timepreset in the transmission-time setting register. If the current timematches with the data-transmission time, or if the current time passesthe data-transmission time, the time comparing unit generates adata-transmission request that requests for data transmission to thecentral management device 6. In such a case, the time comparing unitalso outputs a main-power-source turning-on signal (a startup signal) tothe power-source control unit 111 as well as outputs a data-transmissionrequesting signal to the CPU 102.

Additionally, the time comparing unit compares the current timegenerated by the RTC 104 with the data-acquisition time preset in theacquisition-time setting register. If the current time matches with thedata-acquisition time, or if the current time passes thedata-acquisition time, the time comparing unit generates adata-acquisition request requested from the image-forming devices 1through 5. In such a case, the time comparing unit also outputs themain-power-source turning-on signal (the startup signal) to thepower-source control unit 111 as well as outputs an acquisition-requestsignal to the CPU 102.

The ROM 106 is a read only memory that stores various fixed dataincluding the control program used by the CPU 102. The serialcommunication control unit 107 exchanges a signal with the image-formingdevices 1 through 5. The NCU 108 includes a line control unit 115, an ITdetecting unit 116, a hook-detecting unit 117 and a ringer-detectingunit 118. Each unit included in the NCU 108 functions asdata-transmission-requesting-signal transmitting means, datatransmission means and data reception means, with the CPU 102, the modem109 and the like. The data reception means is means for receivingvarious signals and data including a call signal.

The line control unit 115 controls a call to the central managementdevice 6, and a switching operation to connect the communication line 8to a side of the image-forming devices 1 through 5, or a side of ageneral telephone device (TEL) or a facsimile device (FAX). The ITdetecting unit 116 detects an IT signal transmitted from the centralmanagement device 6 through the communication line 8. This IT signal is,for example, a DTMF signal, which is a combination of codes “*#0#”. Thehook-detecting unit 117 detects a hook. The ringer-detecting unit 118detects a ringer signal (a ringing signal) transmitted from a switchingsystem inside the communication line 8 according to a call out made bythe central management device 6 or an external device such as anexternal facsimile device.

The modem 109 modulates data to be transmitted, and demodulates receiveddata. In detail, the modem 109 carries out digital/analog conversion ofdata to be transmitted to an external device through the communicationline 8, and analog/digital conversion of data received from an externaldevice through the communication line 8. The I/O control unit 110controls input of a signal to each unit, and output of a signal fromeach unit, in the data communication device 7.

The power-source control unit 111 functions as call-origin detectingmeans, data-type detecting means and power-supply control means, withthe CPU 102, the NCU 108 and the like. In detail, the power-sourcecontrol unit 111 keeps the main power source 112 turned on if the datacommunication device 7 is in the normal operation mode. On the otherhand, the power-source control unit 111 keeps the main power source 112turned off of the data communication device 7 is in the energy-savingmode.

Additionally, the power-source control unit 111 turns the main powersource 112 on, if the data-transmission request or the data-acquisitionrequest is generated. Further, the power-source control unit 111 turnsthe main power source 112 on, if receiving the ringer signal from thecommunication line 8, or the startup signal used for starting up thedata communication device 7 from one of the image-forming devices 1though 5. After finishing a process corresponding to a generated orreceived signal, the power-source control unit 111 turns the main powersource 112 off. A detailed description about the power-source controlunit 111 will be given later.

A description will now be given of summarized functions of theimage-forming-device management system according to the secondembodiment. This image-forming-device management system according to thesecond embodiment also has three main functions similar to that of thefirst embodiment, which are communication control (1) from the centralmanagement device 6 to the image-forming devices 1 though 5,communication control (2) from the image-forming devices 1 through 5 tothe central management device 6 or the data communication device 7, andcontrol (3) of the data communication device 7 itself.

Text data transferred between the central management device 6 and thedata communication device 7, text data transferred between the datacommunication device 7 and the personal interface 18 of theimage-forming devices 1 through 5 and text data transferred between thepersonal interface 18 of the image-forming devices 1 through 5 and thePPC controller 31 shown in FIG. 21 are the same as the text datadescribed with reference to FIGS. 10, 11 and 12, respectively.

The communication control (1) from the central management device 6 tothe image-forming devices 1 though 5 includes the above-describedcommunication controls A1, A2 and A3. The data communication device 7performs the communication control (1) by receiving an instructionsignal, that is, either the data-transmission requesting signalrequesting for data transmission or the data-write requesting signalrequesting for writing data, from the central management device 6, andcarrying out the selecting operation to the image-forming devices 1through 5.

A description will now be given of a control when receiving the ringingsignal or the ringer signal at the data communication device 7, withreference to FIG. 23. FIG. 23 is a flowchart showing a control processincluding power-supply control when the data communication device 7receives the ringer signal.

If the ringing signal or the ringer signal is transmitted according to acall out made by an external device from the communication line 8 to thedata communication device 7, the ringer-detecting unit 118 of the NCU108 shown in FIG. 22 detects the ringer signal, and outputs a signalindicating reception of the ringer signal to the power-source controlunit 111. Additionally, when an external telephone device (TEL) or afacsimile device (FAX) detects the ringer signal, and closes a line, thecentral management device 6 transmits the IT signal to the datacommunication device 7 if the central management device 6 is the callorigin. In this case, the IT detecting unit 116 detects the IT signal,and outputs a signal that indicates the detection of the IT signal tothe power-source control unit 111.

At a step S51 shown in FIG. 23, the power-source control unit 111decides whether the data communication device 7 is in the normaloperation mode or the energy-saving mode, in which the main power source112 is tuned off. An operation mode of the data communication device 7can be set to the normal operation mode or the energy-saving mode, byoperating a switch not shown in the figures. If the operation mode ofthe data communication device 7 is the normal operation mode, the datacommunication device 7 interrupts the processes shown in FIG. 23, andcarries out another regular process, which is a later-described processthat is carried out in the energy-saving mode, and excludes thepower-supply control.

On the other hand, if the operation mode of the data communicationdevice 7 is the energy-saving mode, the ringer-detecting unit 118detects whether the ringer signal is received by the data communicationdevice 7, at a step S52. If the ringer-detecting unit 118 detects theringer signal supplied from the communication line 8, the power-sourcecontrol unit 111 proceeds to a step S53, and decides whether the callorigin is the central management device 6. In a case in which the ITdetecting unit 116 detects the IT signal continuously after thedetection of the ringer signal by the ringer-detecting unit 118, thepower-source control unit 111 decides that the call origin is thecentral management device 6, at a step S54. Subsequently, thepower-source control unit 111 turns on the main power source 112 at astep S55, and supplies electricity to units related to communicationincluding the CPU 102 and the modem 109 functioning as the datatransmission means. Consequently, the CPU 102 starts up.

The CPU 102 carries out an initialization process not shown in thefigures after receiving the electricity from the main power source 112in the energy-saving mode. In a case in which the CPU 102 receives textdata having the format shown in FIG. 11 and composing the instructionsignal transmitted continuously after the IT signal from the centralmanagement device 6, by using the NCU 108 and the modem 109, the CPU 102decides a destination of data and a type of the data from theinstruction signal or the text data, at a step S56. It should be notedthat the instruction signal supplied from the central management device6 is either the data-transmission requesting signal or the data-writerequesting signal.

The above-described destination indicates a destination of theinstruction signal. For example, the data communication device 7 and animage-forming device are defined as a destination “2” and a destination“3”, respectively. A field of the distinguishing code of the text datashown in FIG. 11 holds a code indicating a source or a call origin ofthe text data. For example, the central management device 6 is definedas a source “1”. The type of data indicates a type of data that is to betransmitted to the central management device 6, or data that is to bewritten to the destination.

In a case in which the CPU 102 recognizes that a process requested bythe central management device 6 is communication between the datacommunication device 7 and the central management device 6 based on aresult of deciding the destination of the data and the type of the dataat the step S56, the CPU 102 communicates with the central managementdevice 6.

In detail, in a case in which the CPU 102 recognizes that the processrequested by the central management device 6 is transmission of datastored in the data communication device 7 to the central managementdevice 6 according to the instruction signal as the data-transmissionrequesting signal, the CPU 102 transmits data stored in the non-volatileRAM 103 such as data related to the image-forming devices 1 through 5,to the central management device 6 by using the NCU 108 and the modem109. If the CPU 102 can recognize the type of the data that is to betransmitted to the central management device 6 from the result ofdeciding the destination and the type of the data, the CPU 102 transmitsonly data that corresponds to the recognized type, to the centralmanagement device 6 by using the NCU 108 and the modem 109.

On the other hand, in a case in which the CPU 102 recognizes that theprocess requested by the central management device 6 is a data-writeprocess to the data communication device 7 according to the instructionsignal as the data-write requesting signal, the CPU 102 writes data suchas a parameter stored in a field of the information record inside theinstruction signal or the text data received from the central managementdevice 6, in the non-volatile RAM 103.

Additionally, the CPU 102 of the data communication device 7 carries outa communication process including a later-described selecting operation,at a step S58, in a case in which the CPU 102 decides at a step S57 thatthe process requested by the central management device 6 is transmissionof data related an image-forming device as the destination of data amongthe plurality of the image-forming devices 1 though 5 to the centralmanagement device 6, or a data-write process to the image-forming deviceas the destination of the data. In such a case, the CPU 102 outputs aspecific code (a combination of codes) that indicates a predeterminedselecting function composing a selecting signal (SA), and a device codeof the image-forming device to be selected, to the serial communicationinterface RS-485 by using the serial communication control unit 107.

At each image-forming device 1 through 5, the CPU 21 of the personalinterface 18 carries out various processes such as a process to turn onthe main power source 61 if the main power source 61 is off, whenreceiving the selecting signal from the data communication device 7. Adescription about the processes carried out by the CPU 21 will bedescribed later.

The CPU 102 of the data communication device 7 turns off the main powersource 112 by outputting the main-power-source turning-off signal to thepower-source control unit 111 to stop supplying electricity to the unitsrelated to communication including the CPU 102 and the modem 109, afterfinishing the communication with the central management device 6, at astep S60. If the data communication device 7 is in the energy-savingmode, and the IT detecting unit 116 cannot detect the IT signal in apredetermined period, that is, four to twenty seconds after thedetection of the ringer signal by the ringer-detecting unit 118 or thedetection of the hook by the hook-detecting unit 117, the CPU 102 of thedata communication device 7 decides that the call origin is not thecentral management device 6, and finishes the processes shown in FIG. 23with the main power source 112 turned off.

FIGS. 24A and 24B are flowcharts showing a process carried out by theCPU 21 of the personal interface 18 included in each image-formingdevice 1 through 5 during the selecting operation. In addition, FIG. 25is a diagram showing a communication sequence between the personalinterface 18 of one of the image-forming devices 1 through 5 and thedata communication device 7. The personal interface 18 included in eachimage-forming device 1 through 5 is activated by the power supply fromthe sub power source 62, as described above. The CPU 21 of the personalinterface 18 can decide whether the main power source 61 is turned on oroff, according to a condition signal inputted by the main power source61, the condition signal indicating whether the main power source 61 isturned on or off.

When the data communication device 7 receives the ringer signalcorresponding to a call out made by the central management device 6 fromthe communication line 8, the data communication device 7 transmits theselecting signal used for calling an image-forming device, to theimage-forming device. This selecting signal is composed of a specificcode (a combination of codes) indicating a selecting function, and adevice code of the image-forming device to be selected.

The CPU 21 of the personal interface 18 included in the image-formingdevice receives the specific code and the device code, by using theserial communication control unit 28 shown in FIG. 21, and compares thereceived device code with a device code of its own image-forming deviceby using the specific code indicating the selecting function. If thereceived device code matches with the device code of the image-formingdevice, the CPU 21 recognizes that the image-forming device is selectedby the data communication device 7, and starts the process (asub-routine) shown in FIG. 24A and 24B according to a call from a mainroutine.

The CPU 21 initially decides whether the main power source 61 is turnedon, at a step S61. If it is determined at the step S61 that the mainpower source 61 is turned on, the CPU 21 proceeds to a step S68, anddecides whether the CPU 21 has transmitted a negative response or a busysignal to the data communication device 7 at the previous process. Ifthe CPU 21 did not transmit the negative response at the previousprocess, the CPU 21 resets a later-described timer B by initializing atime measured by the timer B, and starts measuring a time by use of thetimer B, at a step S69. Subsequently, the CPU 21 proceeds to a step S70.

On the other hand, if the CPU 21 has transmitted the negative responseto the data communication device 7 at the previous process, the CPU 21skips the step S69, and proceeds to the step S70, in order to use thetimer B that was reset and started during the previous process.

If it is determined at the step S61 that the main power source 61 isturned off, the CPU 21 proceeds to a step S62, and turns on the mainpower source 61 by using the main-power-source control signal, therebysupplying electricity to the PPC controller 31 including the CPU 11,which is a unit related to communication. Subsequently, at a step S63,the CPU 21 transmits a signal instructing initialization of the PPCcontroller 31, to the CPU 11 included in the PPC controller 31, therebymaking the CPU 11 start initializing the PPC controller 31.

At this moment, internal information of the PPC controller 31 is notestablished, and, thus, the image-forming device cannot communicate withthe data communication device 7. Accordingly, at a step S64, the CPU 21of the personal interface 18 transmits a signal (an initializationsignal) indicating that the PPC controller 31 is being initialized or asignal indicating a condition in which the image-forming device isunable to receive data, to the data communication device 7, as well asresets and starts timers A and B.

The timer A is used for carrying out a communication-failure process,for instance, to notify a user about a communication failure bydisplaying information about the communication failure on thetext-display unit 83 of the operation display unit shown in FIG. 5, in acase in which the communication failure occurs between the image-formingdevice and the data communication device 7. Accordingly, a fixed timeoutperiod “Ta” is set longer than a period necessary for completing thecommunication between the image-forming device and the datacommunication device 7. The timer A is reset, and starts measuring timeafter the above-described communication starts. When the time measuredby the timer A passes the timeout period Ta, the timer A timeouts.

The timer B is used for turning off the main power source 61 to saveenergy, in a case in which the image-forming device is unused for afixed period, for instance, an hour. Accordingly, the above-describedfixed time is set as a timeout period “Tb” of the timer B, in advance.The timer B is reset, and starts measuring time according to aninstruction signal from the CPU 11 after the image-forming device startsbeing unused. When the time measured by the timer B passes the timeoutperiod Tb, the timer B timeouts according to the instruction signal fromthe CPU 11.

Additionally, the timer B is reset, and starts measuring the timeaccording to the instruction signal from the CPU 11, when theimage-forming device starts an image forming operation, or when theimage-forming device shifts to a specific operation mode. The timer Brepeats being reset and starting measuring the time at a fixed timing,so that the time measured by the timer B does not pass the timeoutperiod Tb while the image-forming device is carrying out the imageforming operation or is in the specific operation mode. In other words,the timer B prevents the main power source 61 from being turned off,while the image-forming device is carrying out the image formingoperation or is in the specific operation mode. The timeout period Tb isset larger than the timeout period Ta.

After executing the step S64, the CPU 21 of the personal interface 18decides whether the time measured by the timer A passes the timeoutperiod Ta, at a step S65. If it is determined at the step S65 that thetime measured by the timer A passes the timeout period Ta, or the timerA timeouts, the CPU 21 proceeds to a step S72. In other words, if thetimer A timeouts before completion of the initialization of the PPCcontroller 31, the CPU 21 proceeds to the step S72. On the other hand,if it is determined at the step S65 that the time measured by the timerA does not pass the timeout period Ta, or the timer A does not timeout,the CPU 21 proceeds to a step S66, and decides whether the image-formingdevice receives an inquiry signal from the data communication device 7.

If it is determined at the step S66 that the image-forming device doesnot receive the inquiry signal from the data communication device 7, theCPU 21 shifts back to the step S65. On the other hand, if it isdetermined at the step S66 that the image-forming device receives theinquiry signal from the data communication device 7, the CPU 21 proceedsto a step S67, and decides whether the CPU 11 completes theinitialization of the PPC controller 31.

If the image-forming device receives the inquiry signal from the datacommunication device 7, and the CPU 11 completes the initialization ofthe PPC controller 31 before the timer A timeouts, the CPU 21 proceedsto the step S69. If it is determined at the step S67 that the CPU 11does not complete the initialization of the PPC controller 31, the CPU21 shits back to the step S64.

Meanwhile, if the data communication device 7 receives theinitialization signal from the image-forming device, that is, thedestination of the selecting signal, by using the serial communicationcontrol unit 107, the CPU 102 of the data communication device 7 decidesthat the PPC controller 31 of the image-forming device is beinginitialized, and transmits the inquiry signal after two or three secondspasses. If the data communication device 7 receives the initializationsignal from the image-forming device again, the data communicationdevice 7 waits for another two or three minutes, and, then, transmitsthe inquiry signal to the image-forming device, as shown in FIG. 25.

The CPU 21 of the personal interface 18 inside the image-forming deviceproceeds to the step S69, if it is determined at the step S68 that theCPU 21 did not transmit the negative response at the previous process,or if it is determined at the step S67 that the initialization of thePPC controller 31 is completed. At the step S69, the CPU 21 resets andstarts the timer B. Subsequently, at the step S70, the CPU 21 decideswhether the image-forming device can communicate with the datacommunication device 7.

For example, if it is determined at the step S61 that the main powersource 61 is turned on, the image-forming device may be in a specificoperation mode, in which the image-forming device cannot communicatewith the data communication device 7. Alternatively, a communicationfailure may be occurring between the image-forming device and the datacommunication device 7, or the image-forming device may have data to beoutputted. In the above-described cases, the CPU 21 decides that theimage-forming device cannot communicate with the data communicationdevice 7, and proceeds to a step S71.

At the step S71, the transmits the negative response or the busy signalto the data communication device 7. Subsequently, at the step S72, theCPU 21 decides whether the image-forming device satisfies a fixedmain-power-source turning-off condition that enables the CPU 21 to turnoff the main power source 61. If the time measured by the timer B doesnot pass the timeout period Tb, or the timer B timeouts, at the stepS72, the CPU 21 decides that the image-forming device does not satisfythe main-power-source turning-off condition, and returns to the mainroutine in order to shift to another subroutine. On the other hand, ifthe timer B timeouts, or the fixed period passes while the image-formingdevice is unused, the CPU 21 decides that the image-forming devicesatisfies the main-power-source turning-off condition, and proceeds to astep S73. At the step S73, the CPU 21 stops supplying the electricity tothe PPC controller 31 by turning the main power source 61 off, andreturns to the main routine.

Meanwhile, if the data communication device 7 receives the negativeresponse from the image-forming device by using the serial communicationcontrol unit 107, the CPU 102 of the data communication device 7 decidesthat the image-forming device cannot communicate with the datacommunication device 7, and interrupts the selecting operation.Subsequently, the CPU 102 proceeds to a later-described pollingoperation, or the like.

If it is determined at the step S70 that the image-forming device cancommunicate with the data communication device 7, the CPU 21 of thepersonal interface 18 proceeds to a step S74, and transmits anaffirmative response to the data communication device 7 by using theserial communication control unit 28. In addition, the CPU 21 resets andstarts the timers A and B to prepare for the communication failureprocess.

If the data communication device 7 receives the affirmative responsefrom the image-forming device by using the serial communication controlunit 107, the CPU 102 transmits a requesting signal used for carryingout a process requested by the central management device 6, to theimage-forming device by using the serial communication control unit 107.The requesting signal is either the data-transmission requesting signalor the data-write requesting signal. The data-transmission requestingsignal requests transmission of data inside the PPC controller 31 suchas counter information and log information, that are related to theimage-forming device. The data-write requesting signal requests adata-write process to the image-forming device. A field of theinformation record inside the data-write requesting signal holds writingdata, which includes adjusted values or parameters such as a voltagesetting value of a high-voltage unit and a toner-density setting value.

After executing the step S74, the CPU 21 of the personal interface 18decides whether the image-forming device receives the data-transmissionrequesting signal from the data communication device 7 by using theserial communication control unit 28, at a step S75. If it is determinedat the step S75 that the image-forming device receives thedata-transmission requesting signal from the data communication device7, the CPU 21 proceeds to a step S79. At the step S79, the CPU 21obtains data (text data) inside the PPC controller 31 of theimage-forming device as data responding the data-transmission requestingsignal, and transmits the data to the data communication device 7 byusing the serial communication control unit 28. In addition, at the stepS79, the CPU 21 resets and starts the timers A and B. The CPU 21, then,shifts back to the step S75.

Additionally, the CPU 21 controls supplying electricity from the mainpower source 61 to units that need the electricity for obtaining thedata to be transmitted to the central management device 6 among datainside the PPC controller 31, or for writing (rewriting) data in, in thecase in which the image-forming device receives an instruction signal,which is either the data-transmission requesting signal or thedata-write requesting signal. Therefore, the CPU 21 needs to set theunits that need the electricity, in advance, or when receiving theinstruction signal from the data communication device 7. A descriptionabout a process to set the units that need the electricity will be givenlater.

If the data communication device 7 receives the data inside the PPCcontroller 31 in response to the data-transmission requesting signal,from the image-forming device by using the serial communication controlunit 107, the CPU 102 of the data communication device 7 transmits thedata to the central management device 6 by using the NCU 108 and themodem 109.

If the image-forming device does not receive the data-transmissionrequesting signal from the data communication device 7 at the step S75,the CPU 21 proceeds to a step S76, and decides whether the image-formingdevice receives the data-write requesting signal from the datacommunication device 7 by using the serial communication control unit28. If it is determined at the step S76 that the image-forming devicereceives the data-write requesting signal from the data communicationdevice 7, the CPU 21 proceeds to a step S80. At the step S80, the CPU 21instructs the CPU 11 to write or set the writing data stored in thefield of the information record of the data-write requesting signal (thetext data) to the PPC controller 31. Subsequently, the CPU 21 transmitsset data, that is, a value obtained by carrying out a fixed measuringprocess to the writing data written in the PPC controller 31, to thedata communication device 7 by using the serial communication controlunit 28. Additionally, the CPU 21 resets and starts the timers A and B.The CPU 21, then, shifts back to the step S75.

On the other hand, the CPU 102 of the data communication device 7compares the writing data transmitted to the image-forming device byincluding the writing data in the data-write requesting signal, with theset data transmitted from the image-forming device in response to thewriting data, thereby deciding whether the writing data is correctlywritten in the PPC controller 31 of the image-forming device. Inaddition, the CPU 102 transmits an end signal to the image-formingdevice after completing the transmission of the data-transmissionrequesting signal or the data-write requesting signal.

If the image-forming device does not receive the data-write requestingsignal from the data communication device 7 at the step S76, the CPU 21of the personal interface 18 decides whether the image-forming devicereceives the end signal from the data communication device 7 by usingthe serial communication control unit 28, at a step S77. In other words,the CPU 21 decides whether the communication between the image-formingdevice and the data communication device 7 has ended. At a step S78, theCPU 21 decides whether the timer A timeouts, or the time measured by thetimer A passes the timeout period Ta.

The CPU 21 repeats the step S75, S76, S79 or S80 until the image-formingdevice receives the end signal from the data communication device 7before the timer A timeouts. If the image-forming device receives theend signal from the data communication device 7 before the timer Atimeouts, the CPU 21 proceeds to the step S72. Additionally, if thetimer A timeouts before the image-forming device receives the end signalfrom the data communication device 7, the CPU 21 also proceeds to thestep S72.

At the step S72, the CPU 21 decides whether the image-forming devicesatisfies the main-power-source turning-off condition, as describedabove. However, if the CPU 21 shifts to the step S72 from the step S65,S77 or S78, the CPU 21 returns to the main routine, and shift to anothersubroutine, since the timer B does not timeout at the step S72.

In a case in which the CPU 21 shifts to another subroutine while themain power source 61 is turned on, the CPU 21 turns off the main powersource 61, thereby stopping the power supply to all the units includingthe PPC controller 31, when the main switch is turned off, or the timerB timeouts, or the fixed period passes while the image-forming device isunused. Additionally, in a case in which the timer A timeouts, the CPU21 decides that the communication failure occurs between theimage-forming device and the data communication device 7, and carriesout the communication failure process, for instance, to notify a userabout the communication failure by displaying the information about thecommunication failure on the text-display unit 83 of the operationdisplay unit.

As describe above, the data communication device 7 used in theimage-forming-device management system according to the secondembodiment includes the non-volatile RAM 103, the RTC 104, the call-timecontrol unit 105, the NCU 108 and the power-source control unit 111,which are always supplied with the electricity from the battery 101. Inthe energy-saving mode, the power-source control unit 111 decideswhether the call origin is the central management device 6 according toa result of detecting the IT signal by the IT detecting unit 116, in thecase in which the ringer-detecting unit 118 inside the NCU 108 detectsthe ringer signal transmitted by the call out of the external devicefrom the communication line 8.

If it is determined that the call origin is the central managementdevice 6, the electricity is supplied to the units including the CPU 102related to communication, by turning on the main power source 112 of thedata communication device 7.

Accordingly, the CPU 102 receives the instruction signal (the text data)transmitted continuously after the IT signal, by use of the NCU 108 andthe modem 109, and, then, communicates between the data communicationdevice 7 and the central management device 6. For example, the CPU 102transmits the data, which is related to the image-forming devices 1through 5, and is stored in the non-volatile RAM 103, to the centralmanagement device 6 by using the NCU 108 and the modem 109. When the CPU102 finishes the communication between the data communication device 7and the central management device 6, the power-source control unit 111turns off the main power source 112.

Consequently, the data communication device 7 can reduce unnecessaryelectricity consumption as well as can communicate with the centralmanagement device 6 at any time.

If the data communication device 7 turns on the main power source 112according to only the ringer signal, the data communication device 7wastes electricity by turning on the main power source 112 every timethe data communication device 7 receives a telephone call or carries outfacsimile communication, which are unrelated to communication betweenthe data communication device 7 and the central management device 6. Onthe other hand, according to the present invention, the datacommunication device 7 turns on the main power source 112 according toonly a signal from the central management device 6, by detecting boththe ringer signal and the IT signal. Thus, usage efficiency ofelectricity is improved at the data communication device 7.

Additionally, the CPU 102 of the data communication device 7 decideswhether a process requested by the central management device 6 istransmission of data related to an image-forming device to the centralmanagement device 6, according to the instruction signal (thedistinguishing code of the text data) received continuously after theringer signal and the IT signal. If the process requested by the centralmanagement device 6 is the transmission of the data related to theimage-forming device, the data communication device 7 transmits theselecting signal, which composes either the data-transmission requestingsignal or the data-write requesting signal, to the image-forming device,by using the serial communication control unit 107. As a result, the CPU21 of the personal interface 18 included in the image-forming devicesupplies electricity to the PPC controller 31 by turning on the mainpower source 61 if the main power source 61 is turned off.

Accordingly, the image-forming devices 1 through 5 can reduceunnecessary electricity consumption, as well as can communicate with thedata communication device 7 or the central management device 6 at anytime.

Furthermore, if the power-source control unit 111 of the datacommunication device 7 detects that the call origin is a device otherthan the central management device 6, a call by use of a telephonedevice or communication by use of a facsimile device are performed.Consequently, the data communication device 7 can keep the main powersource 112 off, and, thus, can avoid unnecessary electricityconsumption.

A description will now be given of the communication control (2) fromthe image-forming devices 1 through 5 to the central management device 6or the data communication device 7, where the communication control (2)is one of the three main functions of the image-forming-devicemanagement system according to the second embodiment.

The communication control (2) of the image-forming-device managementsystem includes the following five controls F1 through F5, for example.

(F1) In a case in which a failure occurs so that each image-formingdevice 1 through 5 cannot carry out an image forming operation, the CPU11 of the image-forming device transmits data indicating the failure byusing the personal interface 18 immediately to the data communicationdevice 7, where the data communication device 7 transmits the dataindicating the failure (an emergency report) to the central managementdevice 6 through the communication line 8.

(F2) The CPU 11 of each image-forming device 1 through 5 shifts from animage forming mode to a user-request input mode used by a user to inputa necessary request such as a repair request or an equipment-supplyrequest, in response to a key operation carried out by the user on theoperation display unit. The CPU 11, then, displays a user-request inputscreen on the text-display unit 83 of the operation display unit. Whenthe necessary request is inputted, by the user pressing down a fixed keyon the screen, the CPU 11 transmits data indicating the necessaryrequest by using the personal interface 18 immediately to the datacommunication device 7, where the data communication device 7 transmitsthe data (an emergency report) to the central management device 6through the communication line 8.

(F3) The CPU 11 of each image-forming device 1 through 5 transmits dataindicating a total number of forming images or an order of copy paper(emergency-call data) immediately to the data communication device 7 byusing the personal interface 18 every time the total number of formingimages reaches a predetermined number (a reporting-level value), wherethe data communication device 7 transmits the data (an emergency report)to the central management device 6 through the communication line 8.

(F4) The CPU 11 of each image-forming device 1 through 5 transmits dataindicating the total number of forming images to the data communicationdevice 7 by using the personal interface 18 for every predeterminedperiod. AT a preset data-transmission time on a specific day, the CPU102 of the data communication device 7 transmits the data received fromthe image-forming device before the data-transmission time together as anon-emergency report, by using the NCU 108 and the modem 109, to thecentral management device 6 through the communication line 8. Thiscommunication control includes control to transmit the data to thecentral management device 6 without waiting for the data-transmissiontime, in a case in which the number of transmitting the data reaches apredetermined number before the data-transmission time. It should benoted that the data-transmission time is set by the central managementdevice 6, and is stored in the non-volatile RAM 103 inside the datacommunication device 7.

(F5) The CPU 11 of each image-forming device 1 through 5 transmits dataindicating that preventive maintenance is necessary, to the datacommunication device 7 by using the personal interface 18, in a case inwhich the image-forming operation can be started, but an event thatneeds preventive maintenance occurs. This event is, for instance, anevent in which the number or the period which exchangeable parts areused for becomes closer to a predetermined number of times or apredetermined period, or an event in which a sensor reaches a standardlevel.

At a preset data-transmission time on a specific day, the CPU 102 of thedata communication device 7 transmits the data (a non-emergency report)received from the image-forming device before the data-transmission timetogether, by using the NCU 108 and the modem 109, to the centralmanagement device 6 through the communication line 8. This communicationcontrol includes control to transmit the data to the central managementdevice 6 without waiting for the data-transmission time, in a case inwhich the number of transmitting the data received from image-formingdevice reaches a predetermined number. It should be noted that thedata-transmission time is set by the central management device 6, and isstored in the non-volatile RAM 103 inside the data communication device7.

The above-described communication controls (F1 through F5) are performedwhen the data communication device 7 carries out the polling operation.Hence, a description will now be given of processes carried out by thedata communication device 7 and the image-forming devices 1 through 5used in the image-forming-device management system according to thesecond embodiment, during the polling operation, with reference to FIG.10.

The CPU 102 of the data communication device 7 outputs a predeterminedspecific code (a combination of codes) indicating a polling function,and a device code of an image-forming device that is to be selected, tothe serial communication interface RS-485 by using the serialcommunication control unit 107, in the normal operation mode. Thespecific code and the device code compose a polling signal (PA)together.

The CPU 11 of each image-forming device 1 through 5 compares the devicecode that follows the specific code indicating the polling function,with a device code of its own image-forming device, by using thespecific code, if receiving the polling signal from the datacommunication device 7 by use of the personal interface 18. If thedevice code of the image-forming device matches with the device codethat is included in the polling signal supplied from data communicationdevice 7, the image-forming device recognizes that the image-formingdevice is polled by the data communication device 7.

Subsequently, the CPU 11 of an image-forming device polled by the datacommunication device 7 starts communication with the data communicationdevice 7, or transmission of data related to the image-forming device,if the image-forming device has output data or receives adata-transmission request requesting transmission of data to the datacommunication device 7 or the central management device 6. On the otherhand, if the image-forming device does not have the output data, or thepreviously-started communication has ended, the CPU 11 of theimage-forming device transmits an end response indicated by apredetermined specific code (a combination of codes) to the datacommunication device 7 by using the personal interface 18, and, then,terminates the communication between the image-forming device and thedata communication device 7.

If the data communication device 7 receives the end response from theimage-forming device by using the serial communication control unit 107,the CPU 102 of the data communication device 7 shifts to the pollingoperation performed to the next image-forming device.

In addition, in a case in which an image-forming device corresponding tothe device code outputted by the data communication device 7 cannotoutput the end response, the CPU 102 of the data communication device 7finishes the polling operation after a predetermined period passes. Thispolling operation is repeated sequentially by the data communicationdevice 7 to each image-forming device 1 through 5 connected to the datacommunication device 7 in the normal operation mode unless the selectingoperation is performed by the data communication device 7.

The CPU 21 of the personal interface 18 included in each image-formingdevice 1 through 5 can supply the electricity to the PPC controller 31by turning the main power source 61 on, in a case in which theimage-forming device receives the polling signal from the datacommunication device 7 as well as the device code of the receivedpolling signal and the device code of the image-forming device are thesame. The CPU 21 can stop supplying the electricity to the PPCcontroller 31 by turning off the main power source 61 automaticallyafter completion of the communication between the image-forming deviceand the data communication device 7.

The CPU 21 can turn off the main power source automatically, when theimage-forming device satisfies the main-power-source turning-offcondition. The image-forming device satisfies the main-power-sourceturning-off condition, if a fixed period passes after the completion ofthe communication between the image-forming device and the datacommunication device 7, or if a fixed period passes while theimage-forming device is unused.

Additionally, until the initialization of the PPC controller 31 endsafter the main power source 61 is turned on, the CPU 21 can transmit theinitialization signal indicating that the PPC controller 31 is beinginitialized, or the signal indicating that the image-forming devicecannot receive data, to the data communication device 7 in response tothe inquiry signal received from the data communication device 7.

According to the processes performed by the image-forming devices 1though 5 during the polling operation, the image-forming device 1through 5 can reduce unnecessary electricity consumption.

A description will now be given of the control (3) of the datacommunication device 7 itself, which is one of the three main functionsof the image-forming-device management system according to the secondembodiment. This control (3) includes the following controls G1 and G2.

(G1) The control G1 is to read data related to an image-forming devicesuch as a total counter value.

(G2) The control G2 is to return a result of communication from theimage-forming devices 1 through 5 to the data communication device 7according to the communication control (2).

The data communication device 7 controls reading the data related tothe-image-forming device such as the total counter value, by carryingout the selecting operation when a data-acquisition request from theimage-forming device is generated. The data-acquisition request from theimage-forming device is assumed to be generated at a predetermined dataacquisition time, for example, at 0:00 AM once a day.

The data communication device 7 has two memories for a total counter ofeach image-forming device connected to the data communication device 7,which are named a memory A and a memory B. The CPU 102 writes the totalcounter value read by the selecting operation once a day as describedabove, in the memory A. In other words, the call-time control unit 105generates the data-acquisition request to be requested from theimage-forming device, at a predetermined data-acquisition time once aday. Subsequently, the call-time control unit 105 supplies adata-acquisition requesting signal to the CPU 102.

Accordingly, the CPU 102 transmits the selecting signal and thedata-transmission requesting signal sequentially to the image-formingdevices 1 through 5 by use of the serial communication control unit 107.If the data communication device 7 receives the total counter value (thetext data) from one of the image-forming devices 1 through 5 in responseto the selecting signal and the data-transmission requesting signal, theCPU 102 of the data communication device 7 writes the total countervalue in the memory A. Thus, every day, the total counter value writtenin the memory A on the previous day is rewritten over by the totalcounter value of the present day.

It should be noted that the power-source control unit 111 needs to carryout later-described power-supply control if the data communicationdevice 7 is in the energy-saving mode. In addition, the CPU 102 copiesthe total counter value stored in the memory A to the memory B on a dateand time predetermined by the central management device 6 and stored inthe non-volatile RAM 103 of the data communication device 7, once amonth.

The data communication device 7 transmits contents of the memory B tothe central management device 6 by following one of methods H1 and H2described below.

(H1) The central management device 6 reads the total counter valuestored in the memory B of the data communication device 7 after the dateand time on which the contents of the memory A is copied to the memoryB. In detail, the central management device 6 connects itself to thedata communication device 7 by calling the data communication device 7,so that the central management device 6 can communicate with the datacommunication device 7. Subsequently, the central management device 6accesses to the data communication device 7 by transmitting acorresponding data-transmission requesting signal to the datacommunication device 7, and obtains the contents (the total countervalue of each image-forming device 1 through 5) of the memory B, whichis transmitted from the data communication device 7.

(H2) The CPU 102 of the data communication device 7 calls spontaneouslyat a predetermined data-transmission time (a year, a month, a date, anhour and a minute), that is, after the above-described date and time onwhich the contents of the memory A is copied to the memory B, and, then,transmits the total counter value stored in the memory B to the centralmanagement device 6 through the communication line 8 by using the NCU108 and the modem 109. If the operation mode of the data communicationdevice 7 is the energy-saving mode, the data communication device 7needs to carry out the later-described power-supply control. Thedata-transmission time or a call time is set by the central managementdevice 6, and is stored in the non-volatile RAM 103 of the datacommunication device 7.

It should be noted that the data communication device 7 includes aplurality of memories, each being composed of the memories A and B, inthe non-volatile RAM 103 for each image-forming device connected to thedata communication device 7, because various total counter values may beassigned for black/white copy, application copy and color copy, forinstance.

A description will now be given of a data acquisition process carriedout by the data communication device 7 in the energy-saving mode, withreference to FIG. 26. FIG. 26 is a flowchart showing the dataacquisition process carried out by the data communication device 7 inthe energy-saving mode.

The CPU 102 of the data communication device 7 reads out a dataacquisition time “Td” (a year, a month, a date, an hour and a minute)predetermined once a day, from the non-volatile RAM 103, when the mainpower source 112 is turned on for the first time after the datacommunication device 7 is installed. Subsequently, the CPU 102 sets thedata-acquisition time to the call-time control unit 105.

The call-time control unit 105 of the data communication device 7compares the data-acquisition time Td with a current time T generated bythe RTC 104, if the data communication device 7 is in the energy-savingmode. If the current time T matches with the data-acquisition time Td,or if the current time T passes the data-acquisition time Td, thecall-time control unit 105 outputs the main-power-source turning-onsignal to the power-source control unit 111, and, then, outputs adata-acquisition requesting signal to the CPU 102, thereby generating adata-acquisition request used for acquiring data from an image-formingdevice, at a step S81 shown in FIG. 26.

After receiving the main-power-source turning-on signal from thecall-time control unit 105, the power-source control unit 111 turns onthe main power source 112 at a step S82, thereby supplying electricityto units related to communication, which are the CPU 102 and the serialcommunication control unit 107 together functioning as thedata-transmission-requesting-signal transmitting means and the datawriting means.

The CPU 102 carries out the selecting operation at a step S83, whenreceiving the data-acquisition requesting signal from the call-timecontrol unit 105 after being supplied with electricity from the mainpower source 112. According to the selecting operation, the CPU 102transmits the selecting signal and the data-transmission requestingsignal (the text data) sequentially by using the serial communicationcontrol unit 107. In a case in which the data communication device 7receives a total counter value from one of the image-forming devices 1through 5 in response to the selecting signal and the data-transmissionrequesting signal, the CPU 102 writes the total counter value in thememory A of the non-volatile RAM 103.

After writing the total counter value in the memory A, the CPU 102outputs the main-power-source turning-off signal to the power-sourcecontrol unit 111. At a step S84, the power-source control unit 111 turnsoff the main power source 112 by receiving the main-power-sourceturning-off signal from the CPU 102, and stops supplying electricity tothe units related to communication.

As described above, the data communication device 7 used in theimage-forming-device management system according to the secondembodiment includes the non-volatile RAM 103, the RTC 104, the call-timecontrol unit 105, the NCU 108 and the power-source control unit 111,which are always supplied with the electricity from the battery 101. Ifthe data communication device 7 is in the energy-saving mode, thecall-time control unit 105 compares the current time generated by theRTC 104 with the predetermined data-acquisition time. If the currenttime matches with the data-acquisition time, or if the current timepasses the data-acquisition time, the call-time control unit 105generates the data-acquisition request. Accordingly, the power-sourcecontrol unit 111 turns on the main power source 112, thereby supplyingthe electricity to the units including the CPU 102, which are related tocommunication.

The units related to communication obtain data from an image-formingdevice. Subsequently, the power-source control unit 111 turns off themain power source 112, thereby stopping the power supply to the unitrelated to communication. Therefore, the data communication device 7 canreduce unnecessary electricity consumption, as well as can obtain datafrom the image-forming devices 1 through 5 at any time.

A description will now be given of a data transmission process carriedout by the data communication device 7 in the energy-saving mode, withreference to FIG. 17.

The CPU 102 of the data communication device 7 reads out a datatransmission time “Tc” (a year, a month, a date, an hour and a minute)stored in the non-volatile RAM 103 when the main power source 112 isturned on for the first time after the data communication device 7 isinstalled, and sets the data transmission time Tc to the call-timecontrol unit 105.

The call-time control unit 105 compares the current time T generated bythe RTC 104 with the predetermined data transmission time Tc, if thedata communication device 7 is in the energy-saving mode. If the currenttime T matches with the data transmission time Tc, or if the currenttime T passes the data transmission time Tc, the call-time control unit105 outputs the main-power-source turning-on signal to the power-sourcecontrol unit 111, and, then, outputs the data-transmission requestingsignal to the CPU 102, thereby generating a data-transmission requestthat requests for transmitting data to the central management device 6.

The power-source control unit 111 turns on the main power source 112 ifreceiving the main-power-source turning-on signal from the call-timecontrol unit 105, thereby supplying the electricity to the unitsincluding the CPU 102 and the modem 109, which are related tocommunication. In fact, the power-source control unit 111 turns on themain power source 112, and supplies the electricity from the main powersource 112 to the entire data communication device 7.

The CPU 102 calls out the central management device 6 by using the NCU108 after being supplied with the electricity from the main power source112, and receiving the data-transmission requesting signal from thecall-time control unit 105. Subsequently, the CPU 102 reads out datarelated to the image-forming devices 1 through 5 from the non-volatileRAM 103, and transmits the data to the central management device 6 byusing the NCU 108 and the modem 109. After completing the transmissionof the data to the central management device 6, the CPU 102 outputs themain-power-source turning-off signal to the power-source control unit111, thereby turning off the main power source 112. Consequently, themain power source 112 stops supplying the electricity to the unitsincluding the CPU 102 and the modem 109, which are related tocommunication.

Alternatively, the call-time control unit 105 compares the current timeT generated by the RTC 104 with the data-transmission time Tc, anddecides whether the non-volatile RAM 103 stores the data related to theimage-forming devices 1 through 5 if the current time T becomes equal tothe data-transmission time Tc, or if the current time T passes thedata-transmission time Tc. The call-time control unit 105 may generatethe data-transmission request if the call-time control unit 105 decidesthat the non-volatile RAM 103 stores the data related to theimage-forming devices 1 through 5.

Alternatively, the call-time control unit 105 decides whether thenon-volatile RAM 103 stores the data related to the image-formingdevices 1 through 5. If it is determined that the non-volatile RAM 103stores the data related to the image-forming devices 1 through 5, thecall-time control unit 105 compares the current time T generated by theRTC 104 with the data-transmission time Tc preset for the data.Accordingly, the call-time control unit 105 can generate thedata-transmission request if the current time T matches with thedata-transmission time Tc, or if the current time T passes thedata-transmission time Tc.

Alternatively, the call-time control unit 105 decides whether thenon-volatile RAM 103 stores the data related to the image-formingdevices 1 through 5. If it is determined that the non-volatile RAM 103stores the data related to the image-forming devices 1 through 5, thecall-time control unit 105 sets the data-transmission time Tc for thedata. Subsequently, the call-time control unit 105 compares the currenttime T generated by the RTC 104 with the data-transmission time Tc.Accordingly, the call-time control unit 105 can generate thedata-transmission request if the current time T matches with thedata-transmission time Tc, or if the current time T passes thedata-transmission time Tc.

Alternatively, it is assumed that a data transmission time is set foreach data item that is related to the image-forming devices 1 through 5,and is stored in the non-volatile RAM 103. For example, thedata-transmission time Tc is given for the total counter value of eachimage-forming device 1 through 5. The call-time control unit 105compares the data-transmission time Tc set for the total counter valueof an image-forming device, with the current time T generated by the RTC104. If the current time T matches with the data-transmission time Tc,or if the current time T passes the data-transmission time Tc, thecall-time control unit 105 generates the data-transmission request thatrequests for transmission of data to the central management device 6.

Subsequently, the CPU 102 reads out the total counter value of theimage-forming device from the non-volatile RAM 103, and transmits thetotal counter value to the central management device 6 by using the NCU108 and the modem 109. The CPU 102 does not turn off the main powersource 112 by using the power-source control unit 111 immediately afterthe transmission of the total counter value. Instead, the CPU 102searches through the non-volatile RAM 103 for other data items thatshould also be transmitted to the central management device 6. If thenon-volatile RAM 103 stores a data item that should be transmitted tothe central management device 6, the CPU 102 reads out the data itemfrom the non-volatile RAM 103, and transmits the data to the centralmanagement device 6 by using the NCU 108 and the modem 109, continuouslyafter the transmission of the total counter value.

If the data communication device 7 has an occupied time, for instance,five to ten minutes, before the next data transmission to the centralmanagement device 6, the CPU 102 sets the next data-transmission time tothe call-time control unit 105, and, then, outputs the main-power-sourceturning-off signal to the power-source control unit 111 to turn off themain power source 112. In addition, the CPU 102 preferably stores atransmission result as a transmission log in the non-volatile RAM 103,and, then, clears information about data transmission to the centralmanagement device 6, in a case in which the data transmission wassuccessful.

Additionally, in a case in which the central management device 6 is busywhen the data communication device 7 calls out the central managementdevice 6, the data communication device 7 cannot transmit data to thecentral management device 6 because of a communication error. Thus, thedata communication device 7 transmits the data afterwards by calling outthe central management device 6 again. In detail, the data communicationdevice 7 preferably calls out the central management device 6 after are-call period passes. Alike the above-described example, the CPU of thedata communication device 7 may set the next data-transmission time tothe call-time control unit 105, and may call out the central managementdevice 6 at the next data-transmission time.

As described above, the data communication device 7 used in theimage-forming-device management system according to the secondembodiment includes the non-volatile RAM 103, the RTC 104, the call-timecontrol unit 105, the NCU 108 and the power-source control unit 111,which are always supplied with the electricity from the battery 101. Inthe energy-saving mode, the call-time control unit 105 compares thecurrent time generated by the RTC 104 with the predetermineddata-transmission time. If the current time matches with thedata-transmission time, or if the current time passes thedata-transmission time, the call-time control unit 105 generates thedata-transmission request.

Accordingly, the power-source control unit 111 turns on the main powersource 112, thereby supplying the electricity to the units including theCPU 102, which are related to communication. After the units related tocommunication complete data transmission to the central managementdevice 6, the power-source control unit 111 turns off the main powersource 112. Consequently, the data communication device 7 can reduceunnecessary electricity consumption as well as can carry out datatransmission to the central management device 6 at any time.

A description will now be given of a power-supply control process and apower-supply part setting process carried out by the CPU 21 of thepersonal interface 18 included in each image-forming device 1 through 5,with reference to FIGS. 27 through 34. FIG. 27 is a block diagramshowing a structure of units included in each image-forming device 1through 5 and a power-supply circuit.

In a case in which each image-forming device 1 through 5 receives theinstruction signal, that is, either the data-transmission requestingsignal or the data-write requesting signal, from the data communicationdevice 7, the CPU 21 of the personal interface 18 inside eachimage-forming device 1 though 5 carries out power-supply control tosupply electricity from the main power source 61 to a part, which needspower supply for acquiring data to be transmitted to the centralmanagement device 6, or for writing or rewriting data. The CPU 21 needsto set a part that needs power supply in order to carry out thepower-supply control.

Control to set the part that needs power supply includes the followingcontrols I1 and I2.

(I1) The CPU 11 of each image-forming device 1 through 5 sets a partthat needs power supply, in accordance with an operation signaloutputted by a key operation from an operation display unit.

(I2) The CPU 11 sets a part that needs power supply, in accordance witha type of data that is added to an instruction signal transmitted fromthe data communication device 7 or the central management device 6, forexample, a type of data that should be transmitted to the centralmanagement device 6.

A detailed description will initially given of the control 11. In thenormal operation mode, the CPU 11 of each image-forming device 1 through5 can set an SP mode, that is, a mode used by a service, by a keyoperation on the operation display unit. Additionally, the CPU 11 candisplay a power-supply mode setting screen on the text-display unit 83of the operation display unit shown in FIG. 5, as shown in FIG. 28.

Every time an ON/OFF key corresponding to each unit displayed on thepower-supply mode setting screen is pressed, the CPU 11 switches anON/OFF display of the key. The CPU 11, then, sets a unit correspondingto a key displayed as “ON” to a part that needs power supply, and sets aunit corresponding to a key displayed as “OFF” to a part that does notneed the power supply.

Accordingly, the CPU 21 of the personal interface 18 turns on the mainpower source 61, and supplies the electricity from the main power source61 to units preset as parts that need power supply, in addition to thePPC controller 31 including the CPU 11, which is related tocommunication. On the other hand, the CPU 21 continues not supplying theelectricity from the main power source 61 to units other than the PPCcontroller 31 and the units preset as the parts that need power supply.

FIG. 27 shows the main power source 61, the personal interface 18, thePPC controller 31, relays 151 through 154, switches 151 a through 154 a,an operation display unit 161, a fixing unit 162, an ADF 163 and asorter 164. The relays 151 through 154 are included in the PPCcontroller 31 or attached to the PPC controller 31 from outside.

The relay 151 supplies the electricity from the main power source 61 tothe operation display unit 161 by closing the switch 151 a, when therelay 151 shifts to an operating state according to a drive signalsupplied from the CPU 21. The relay 152 supplies the electricity fromthe main power source 61 to the fixing unit 162 by closing the switch152 a, when the relay 152 shifts to the operating state according to thedrive signal supplied from the CPU 21. The relay 153 supplies theelectricity from the main power source 61 to the ADF (a documenttransmission unit) 163 by closing the switch 153 a, when the relay 153shifts to the operating state according to the drive signal suppliedfrom the CPU 21. Additionally, the relay 154 supplies the electricityfrom the main power source 61 to the sorter (a copy sheetafter-processing unit) 164 by closing the switch 154 a, when the relay154 shifts to the operating state according to the drive signal suppliedfrom the CPU 21.

The CPU 21 of the personal interface 18 included in each image-formingdevice 1 through 5 turns on the main power source 61 to supply theelectricity to the PPC controller including the CPU 11, if the mainpower source 61 is turned off in the energy-saving mode when the CPU 21receives the instruction signal from the data communication device 7. Inaddition, the CPU 21 also supplies the electricity from the main powersource 61 to a unit preset as the part that needs power supply, byoperating a relay corresponding to the unit to close a switchcorresponding to the relay. For example, in a case in which only thefixing unit 162 is preset as the part that needs power supply, the CPU21 operates the relay 152 to close the switch 152 a, and supplies theelectricity from the main power source 61 to the fixing unit 162.

As described above, each image-forming device 1 through 5 can preset apart or a unit that needs power supply, and, thus, can carry out datatransmission effectively without supplying electricity to a partunnecessary for the data transmission. Alternatively, each image-formingdevice 1 through 5 may set the part that needs power supply by a remotecontrol operation according to an instruction signal supplied from thecentral management device 6. If a main switch not shown in the figuresis turned on, the CPU 21 turns on all the relays 151 through 154 toclose their switches 151 a, through 154 a, and supplies the electricityfrom the main power source 61 to all the units shown in FIG. 27.

Next, a description will be given of the control I2. Here, thedescription is particularly given of the control I2 to supplyelectricity from the main power source 61 to only the fixing unit 162.FIG. 29 is a diagram showing a communication sequence between thepersonal interface 18 of one of the image-forming devices 1 through 5and the data communication device 7. In FIG. 29, an affirmative signaland a negative signal are indicated as ACK and EOT, respectively. Afixing-temperature requesting signal (text data) corresponds to thedata-transmission requesting signal, and includes power-source controlinformation, which indicates whether power supply is necessary for aunit.

The fixing-temperature requesting signal has a structure shown in FIG.30, for instance. Additionally, the power-source control informationincluded in the fixing-temperature requesting signal has contents shownin FIG. 31, for example, and indicates whether power supply is necessaryfor individual units. Information indicating an actual request for afixing temperature has contents shown in FIG. 32, for instance.

The personal interface 18 included in one of the image-forming devices 1through 5 turns on the main power source 61 to supply the electricity tothe PPC controller 31 including the CPU 11, in a case in which thepersonal interface 18 receives the fixing-temperature requesting signalwhile the main power source 61 is turned off due to the energy-savingmode.

Additionally, the personal interface 18 extracts the power-sourcecontrol information from the fixing-temperature requesting signal, andanalyzes the power-source control information. The personal interface18, then, controls the main power source 61 according to bits “0” and“1”, which are included in the power-source control information. Forexample, if a bit corresponding to the fixing unit 162 is “1”, thepersonal interface 18 recognizes that the fixing unit 162 is set as apart that needs power supply, and, then, operates the relay 152 to closethe switch 152 a, thereby supplying the electricity from the main powersource 61 to the fixing unit 162. Accordingly, the CPU 11 of the PPCcontroller 31 can acquire a set value of a fixing temperature from thefixing unit 162.

In the second embodiment, the CPU 11 of each image-forming device 1through 5 turns off the main power source 61 to stop supplying theelectricity to all the units including the PPC controller 31 related tocommunication, after transmitting the set value of the fixingtemperature acquired from the fixing unit 162 to the data communicationdevice 7. Alternatively, the CPU 11 can stop operating the relay 152 tomake the relay 152 open the switch 152 a to stop supplying theelectricity from the main power source 61 to the fixing unit 162, in acase in which the CPU 11 receives an instruction signal shown in FIG. 33from the data communication device 7 after transmitting the set value ofthe fixing temperature acquired from the fixing unit 162 to the datacommunication device 7.

If an image-forming device is in the normal operation mode, theimage-forming device may be carrying out a printing process or an imageforming process when the personal interface 18 of the image-formingdevice receives an information-modification requesting signal from thecentral management device 6 through the data communication device 7.This information-modification requesting signal is one type of thedata-write requesting signal that requests modification of informationabout a specific area in an image-forming device.

For example, the information-modification requesting signal may requestmodification of a value of a current flowing through a photosensitivedrum. If the value of the current (a drum current) flowing through thephotosensitive drum is modified while the image-forming device iscarrying out the image forming process, image density may differ with alocation on a single copy sheet, as shown in FIG. 34. Consequently,information recorded on the copy sheet by the image-forming device maybecome unusable. In addition, if the CPU 11 of an image-forming devicedoes not have satisfactory processing ability, the image-forming devicemay not be able to carry out an image forming process and acommunication process between the image-forming device and the datacommunication device 7 concurrently.

Accordingly, the CPU 11 of each image-forming device 1 through 5 carriesout the following controls J1 through J4, in addition to theabove-described power-supply control.

(J1) In a case in which the CPU 11 modifies information related to imageformation during an image forming process, the CPU 11 modifies theinformation after completing a current image forming process beingcarried out to a copy sheet. Accordingly, image recorded on a singlecopy sheet by the image forming process does not change itscharacteristics during the image forming process. The informationrelated to image formation includes conditions of a drum current, afixing temperature, a ramp voltage and a laser diode.

(J2) In a case in which processing ability of the CPU 11 of animage-forming device is low so that the CPU 11 has difficulty to carryout a communication process and an internal process such as an imageforming process concurrently, the CPU 11 notifies the personal interface18 that the image-forming device is busy, simultaneously as theimage-forming device starts the internal process. The personal interface18 does not pass an instruction signal, that is, either thedata-transmission requesting signal or the data-write requesting signal,received from the data communication device 7 or the central managementdevice 6, until the personal interface 18 receives a ready signalindicating that the image-forming device is ready for carrying out thenext process, from the CPU 11. The CPU 11 supplies the ready signal tothe personal interface 18 when the image-forming device completes theinternal process. Consequently, the CPU 11 shifts the image-formingdevice to a state in which the image-forming device can communicate withthe data communication device 7 or the central management device 6.

(J3) In a case in which processing ability of the CPU 11 of animage-forming device is low, the CPU 11 notifies the personal interface18 that the image-forming device is busy by supplying a busy signalthereto, simultaneously as the image-forming device starts its internalprocess such as an image forming process. The personal interface 18 doesnot pass the instruction signal, that is, either the data-transmissionrequesting signal or the data-write requesting signal, received from thedata communication device 7 or the central management device 6, untilthe personal interface 18 receives the ready signal indicating that theimage-forming device is ready for carrying out the next process, fromthe CPU 11. The CPU 11 supplies the ready signal to the personalinterface 18 when the image-forming device completes the internalprocess. Consequently, the CPU 11 shifts the image-forming device to thestate in which the image-forming device can communicate with the datacommunication device 7 or the central management device 6.

If the personal interface 18 receives the instruction signal from thecentral management device 6 and receives the busy signal from the CPU11, the personal interface 18 transmits the busy signal to the centralmanagement device 6 in response to the instruction signal receivedtherefrom. Thus, the central management device 6 can decide whether theimage-forming device is currently operating, according to the busysignal transmitted from the image-forming device.

(J4) In a case in which the data communication device 7 or the centralmanagement device 6 carries out an emergency process to an image-formingdevice, a communication process between the image-forming device and thedata communication device 7 or the central management device 6 is set asa first priority over a process being carried out by the image-formingdevice, by temporarily prohibiting the process being carried out by theimage-forming device.

For example, in a case in which the image-forming device iscommunicating with the data communication device 7 or the centralmanagement device 6 when recognizing an operation signal transmitted tothe image-forming device according to a print key 73 (a start button)that is turned-on, the image-forming device ignores the operationsignal, thereby temporarily prohibiting the process being carried out bythe image-forming device, and setting the communication process as thefirst priority.

If the data communication device 7 is in the energy-saving mode, and itsmain power source 61 is turned off, data inside the image-formingdevices 1 through 5 cannot be transmitted to the central managementdevice 6 through the data communication device 7 instantaneously sincethe data communication device 7 cannot transmit the polling signal tothe image-forming devices 1 through 5.

Accordingly, it is considered that the main power source 112 of the datacommunication device 7 is turned on in a case in which the main powersource 61 of an image-forming device transmitting data is turned on byan operation of a main switch. In detail, the data communication device7 and each image-forming device 1 through 5 are connected as shown inFIGS. 35 and 36. The image-forming devices 3, 4 and 5 are omitted fromFIGS. 35 and 36.

FIG. 35 is a block diagram showing an example of a connection betweenthe data communication device 7, and the image-forming devices 1 and 2.The image-forming devices 3, 4 and 5 are omitted from FIG. 35, but are,in fact, connected to the data communication device 7 in the same manneras the image-forming devices 1 and 2.

Each image-forming device 1 through 5 outputs a power-source voltage +5Vvia a diode 201, and is connected with the data communication device 7through four cables including an output line of the diode 201, as shownin FIG. 35. In a case in which a plurality of the image-forming devices1 through 5 are connected together to the data communication device 7,as shown in FIG. 35, the diode 201 prevents an output voltage (thepower-source voltage) +5V of the main power source 61 of animage-forming device from interfering another image-forming devicehaving the lower output voltage or having its main power source 61turned off.

At each image-forming device 1 through 5, the main power source 61 isturned on, and supplies the electricity to the entire image-formingdevice, if the main switch is turned on. Accordingly, the power-sourcevoltage +5V is inputted to the data communication device 7 from animage-forming device whose main power source 61 is turned on.Subsequently, the power-source control unit 111 of the datacommunication device 7 detects the power-source voltage +5V suppliedfrom the image-forming device, and, thus, recognizes that the main powersource 61 of one of the image-forming devices 1 through 5 is turned on.Consequently, the power-source control unit 111 turns on the main powersource 112 of the data communication device 7, and supplies theelectricity from the main power source 112 to the units including theCPU 102, the serial communication control unit 107 and the modem 109,which are related to communication.

Subsequently, the CPU 102 of the data communication device 7 acquiresdata related to the image-forming device whose main power source 61 isturned on, by carrying out the above-described selecting operation, anddecides a type of the acquired data. If the CPU 102 decides that thedata is emergency-call data, which is, data that indicates a criticalfailure and should be transmitted to the central management device 6immediately, the CPU 102 transmits the emergency-call data to thecentral management device 6 by using the NCU 108 and the modem 109.

In the case in which the CPU 102 of the data communication device 7acquires the data inside the image-forming device whose main powersource 61 is turned on by carrying out the selecting operation, the CPU102 transmits the selecting signal to the image-forming device by usingthe serial communication control unit 107. By receiving the selectingsignal from the data communication device 7, the CPU 11 of theimage-forming device transmits the data to the data communication device7 by using the serial communication control unit 28 of the personalinterface 18. subsequently, the CPU 102 of the data communication device7 receives the data from the image-forming device by using the serialcommunication control unit 107. The detail description about thisselecting operation is previously given.

If the CPU 102 of the data communication device 7 decides that the dataacquired from the image-forming device is data such as the total countervalue whose degree of urgency is low, the CPU 102 writes the data in thenon-volatile RAM 103. The CPU 102 turns off the main power source 112 byuse of the power-source control unit 111, thereby stopping the powersupply to parts related to communication, after transmitting the dataacquired from the image-forming device whose main power source 61 isturned on, to the central management device 6, or after writing the datain the non-volatile RAM 103.

The call-time control unit 105 outputs the data-transmission requestingsignal to the CPU 102, in a case in which a current time matches withthe data-transmission time set in the call-time control unit 105, or thecurrent time passes the data-transmission time, at a timing, at whichthe data communication device 7 transmits the data acquired from theimage-forming device to the central management device 6. Accordingly,the CPU 102 can transmit initially acquired data to the centralmanagement device 6 by using the NCU 108 and the modem 109, and, then,can transmit the data such as the total counter value stored in thenon-volatile RAM 103 to the central management device 6 by using the NCU108 and the modem 109.

Subsequently, the CPU 102 turns off the main power source 112 by use ofthe power-source control unit 111, thereby stopping the power supply tothe parts related to communication, after transmitting the data acquiredfrom the image-forming device whose main power source 61 is turned on,to the central management device 6, or after writing the data in thenon-volatile RAM 103.

On the other hand, if the turned-on main power source 61 of theimage-forming device is turned off, the power-source voltage +5V is notinputted to the data communication device 7. Accordingly, thepower-source control unit 111 becomes unable to detect the power-sourcevoltage +5V, and, thus, recognizes that the main power source 61 of theabove-described image-forming device is turned off. Subsequently, thepower-source control unit 111 turns off the main power source 112,thereby stopping the power supply to the parts related to communication.

However, if the data communication device 7 is communicating with thecentral management device 6 or is carrying out its internal process, theCPU 102 outputs a prohibiting signal to the power-source control unit111, thereby prohibiting the power-source control unit 111 to turn offthe main power source 112, in order to prevent the main power source 112from being turned off. After the data communication device 7 completesthe communication with the central management device 6 or the internalprocess, the CPU 102 outputs the power-source turning-off signal to thepower-source control unit 111 to turnoff the main power source 112.

As described above, in the case in which one of the image-formingdevices 1 through 5 is supplied with the electricity entirely after itsmain power source 61 is turned on because of the operation of the mainswitch, the data communication device 7 is supplied with thepower-source voltage +5V from the image-forming device whose main powersource 61 is turned on. At the data communication device 7, thepower-source control unit 111 recognizes that the main power source 61of one of the image-forming devices 1 through 5 is turned on, bydetecting the power-source voltage +5V, and, then, turns on the mainpower source 112 to supply the electricity from the main power source112 to the parts including the CPU 102, which are related tocommunication.

The data communication device 7 acquires data from the image-formingdevice whose main power source 61 is turned on, and transmits the datato the central management device 6, by use of the parts related tocommunication. Alternatively, the data communication device 7 writes thedata acquired from the image-forming device in the non-volatile RAM 103.After transmitting the data to the central management device 6 orwriting the data in the non-volatile RAM 103, the power-source controlunit 111 turns off the main power source 112, thereby stopping the powersupply from the main power source 112 to the parts related tocommunication. Alternatively, the power-source control unit 111 turnsoff the main power source 112, after the data communication device 7recognizes that the turned-on main power source 61 of the image-formingdevice is turned off. Accordingly, the data communication device 7 canreduce unnecessary electricity consumption. Additionally, theimage-forming devices can carry out data transmission to the datacommunication device 7 or the central management device 6 at any time.

FIG. 36 is a block diagram showing another example of the connectionbetween the data communication device 7, and the image-forming devices 1and 2. The image-forming devices 3, 4 and 5 are omitted from FIG. 36,but are, in fact, connected to the data communication device 7 in thesame manner as the image-forming devices 1 and 2.

At each image-forming device 1 through 5, if the main switch is turnedon, the main power source 61 is turned on, and supplies electricity tothe entire image-forming device. Subsequently, the CPU 21 of thepersonal interface 18 recognizes that the electricity is supplied to theentire image-forming device, and transmits a startup signal to the datacommunication device 7 by using the serial communication control unit28.

At the data communication device 7, the serial communication controlunit 107 includes a startup-signal detecting unit 211 always suppliedwith electricity from the battery 101, where the startup-signaldetecting unit 211 outputs the main-power-source turning-on signal tothe power-source control unit 111 if detecting the startup signaltransmitted from one of the image-forming devices 1 through 5. Afterreceiving the main-power-source turning-on signal from thestartup-signal detecting unit 211 included in the serial communicationcontrol unit 107, the power-source control unit 111 turns on the mainpower source 112, and supplies electricity from the main power source112 to parts including the CPU 102, the serial communication controlunit 107 and the modem 109, which are related to communication.

Subsequently, the CPU 102 acquires data inside the image-forming devicewhose main power source 61 is turned on, by carrying out theabove-described selecting operation, and decides a type of the acquireddata. If the acquired data is emergency-call data that indicates afailure and should be transmitted to the central management device 6immediately, the CPU 102 transmits the emergency-call data to thecentral management device 6 by using the NCU 108 and the modem 109.

If deciding that the acquired data is data such as the total countervalue whose degree of urgency is low, the CPU 102 writes the data in thenon-volatile RAM 103.

The CPU 102 turns off the main power source 112 by use of thepower-source control unit 111, thereby stopping the power supply to theparts related to communication, after transmitting the data acquiredfrom the image-forming device whose main power source 61 is turned on,to the central management device 6, or after writing the data in thenon-volatile RAM 103.

The call-time control unit 105 outputs the data-transmission requestingsignal to the CPU 102, in a case in which a current time matches withthe data-transmission time set in the call-time control unit 105, or thecurrent time passes the data-transmission time, at a timing, at whichthe data communication device 7 transmits the data acquired from theimage-forming device to the central management device 6. Accordingly,the CPU 102 can transmit initially acquired data to the centralmanagement device 6 by using the NCU 108 and the modem 109, and, then,can transmit the data such as the total counter value stored in thenon-volatile RAM 103 to the central management device 6 by using the NCU108 and the modem 109.

Subsequently, the CPU 102 turns off the main power source 112 by use ofthe power-source control unit 111, thereby stopping the power supply tothe parts related to communication, after transmitting the data acquiredfrom the image-forming device whose main power source 61 is turned on,to the central management device 6, or after writing the data in thenon-volatile RAM 103.

In the image-forming device whose main power source 61 is turned on, theCPU 21 of the personal interface 18 turns off the main power source 61,and stops supplying the electricity from the main power source 61 to theparts other than the personal interface 18 that are related tocommunication, after transmitting the data to the data communicationdevice 7.

As described above, if each image-forming device 1 through 5 is suppliedentirely with the electricity from the main power source 61 after themain power source 61 is turned on according to an individual operationof its main switch, the CPU 21 of the personal interface 18 transmitsthe startup signal to the data communication device 7 by using theserial communication control unit 28.

In the data communication device 7, the power-source control unit 111turns on the main power source 112 in the case in which thestartup-signal detecting unit 211 of the serial communication controlunit 107 detects the startup signal transmitted from one of theimage-forming devices 1 through 5. Subsequently, the main power source112 supplies the electricity to the parts including the CPU 102 that arerelated to communication. The CPU 102 acquires the data from theimage-forming device whose main power source 61 is turned on, andtransmits the data to the central management device 6, by using theparts related to communication. Alternatively, the CPU 102 writes thedata acquired from the image-forming device, in the non-volatile RAM103.

After the CPU 102 completes transmitting the data to the centralmanagement device 6 or writing the data in the non-volatile RAM 103, thepower-source control unit 111 turns off the main power source 112, andstops supplying the electricity to the parts related to communication.Accordingly, the data communication device 7 can reduce unnecessaryelectricity consumption. In addition, the image-forming devices 1through 5 can carry out data transmission to the data communicationdevice 7 or the central management device 6 at any time.

Additionally, in the image-forming device whose main power source 61 isturned on, the CPU 21 of the personal interface 18 turns off the mainpower source 61, and stops supplying the electricity from the main powersource 61 to the parts other than the personal interface 18 that arerelated to communication, after transmitting the data to the datacommunication device 7. Accordingly, the image-forming devices 1 through5 can reduce unnecessary electricity consumption.

In the above-described example, the main power source 61 is turned on ifthe main switch is turned on at each image-forming device 1 through 5.In the case in which the electricity is supplied from the main powersource 61 to the entire image-forming device, the CPU 21 of the personalinterface 18 recognizes that the electricity is supplied to the entireimage-forming device, and transmits the startup signal to the datacommunication device 7 by using the serial communication control unit28. Alternatively, the CPU 21 of the personal interface 18 can supplythe electricity from the main power source 61 to the parts including theCPU 11 that are related to communication by turning on the main powersource 61, in the case in which the data-transmission request isgenerated to request for data transmission to the data communicationdevice 7.

The data-transmission request is preferably generated as follows. Forexample, the RTC 12 compares a current time generated by a clockfunction with the predetermined data-transmission time. If the currenttime matches with the data-transmission time, or if the current timepasses the data-transmission time, the RTC 12 generates thedata-transmission request requesting for the data transmission to thedata communication device 7.

Additionally, in the case in which the data-transmission request isgenerated for the data transmission to the data communication device 7,the controls are preferably carried out to supply the electricity fromthe main power source 61 to a part that needs power supply for acquiringdata that should be transmitted to the central management device 6 amongdata included in the PPC controller 31, and to stop the power supply tothe part after completion of transmission of the data to the datacommunication device 7. In order to carry out the above-describedcontrols, each image-forming device 1 through 5 initially needs to setthe part that needs power supply. This process to set the part thatneeds power supply is described above, and, thus, a description of theprocess is omitted here.

Additionally, in the case in which the power-source control unit 111 ofthe data communication device 7 receives the main-power-sourceturning-on signal from the startup-signal detecting unit 211 of theserial communication control unit 107, the power-source control unit 111turns on the main power source 112, and may supply the electricity fromthe main power source 112 to only parts, that are, the CPU 102, the ROM106 and the serial communication control unit 107 necessary for decidinga type of data acquired from an image-forming device whose main powersource 61 is turned on.

Subsequently, the CPU 102 acquires the data from the image-formingdevice whose main power source 61 is turned on. If CPU 102 decides thatthe data acquired from the image-forming device is emergency-call data,the CPU 102 may supply the electricity by use of the power-sourcecontrol unit 111 from the main power source 61 to parts related tocommunication, in fact, the modem 109 and the like, since the otherparts related to communication are already supplied with the electricityfrom the main power source 61.

Furthermore, the data communication device 7 can be set to the normaloperation mode or the energy-saving mode selectively in theimage-forming-device management system according to the secondembodiment. Instead, the data communication device 7 can be set to theenergy-saving mode at all times, and can hold the main power source 112turned off.

A description will now be given of a facsimile (FAX) compound deviceused in an image-forming-device management system according to a thirdembodiment of the present invention.

FIG. 37 is a block diagram showing a structure of a main unit of thefacsimile compound device used in the image-forming-device managementsystem according to the third embodiment. The facsimile compound deviceshown in FIG. 37 includes a CIG4 301, an NCU 302, an FCU 303, a printercontroller 304, a scanner 305, a plotter 306, a personal interface (PI)307, an LADP 308, a main control unit 309, a main power source 310, asub power source 311 and a power-supply control unit 312. In addition,the facsimile compound device includes an operation display unit notshown in the figures.

The CIG 4 301 is a G4 unit of a facsimile device, and is always suppliedwith electricity from the sub power source 311. The NCU 302 is a networkcontrol unit always supplied with the electricity from the sub powersource 311, and carries out connection of a line, disconnection of aline, detection of a line being connected, and the like. The FCU 303 isa facsimile control unit that controls communication with an externalfacsimile device, and includes a CPU 321, a ROM 322, a RAM 323, a RTC324, a UART 325, a VIF 326, a BUSCNT 327, a DCR 328, a memory 329, aPORT 330, a FAX modem 331, a COMCNT 332, an AFE 333, a DTMF 334, and thelike.

The CPU 321 is a central processing unit that controls the entire FCU303 collectively by following a control program stored in the ROM 322,and functions as power-supply part setting means. The ROM 322 is a readonly memory that stores various types of fixed data including thecontrol program used by the CPU 321. The RAM 323 is a temporarilystoring memory such as a work memory used by the CPU 321 for processingdata.

The RTC 324 has a function as data-transmission request generating meansthat includes time generating means, and is always supplied with theelectricity from the sub power source 311. In detail, the RTC 44includes a time generating unit, a facsimile-transmission-time settingregister and a time comparing unit. The time generating unit generates acurrent time (a year, a month, a date, an hour and a minute). Thefacsimile-transmission-time setting register sets afacsimile-transmission time, at which image data for facsimilecommunication is transmitted to an external facsimile device.

In addition, the-time comparing unit compares the current time generatedby the time generating unit with the facsimile-transmission time presetin the facsimile-transmission-time setting register. The time comparingunit generates a facsimile-transmission request that requests facsimiletransmission to a predetermined destination (an external facsimiledevice), if the current time and the facsimile-transmission time matchwith each other, or if the current time passes thefacsimile-transmission time.

This RTC 324 is supplied with the electricity from the sub power source311 different from the main power source 310, and, thus, can generate anaccurate current time even if the main power source is turned off.Alternatively, the RTC 324 may include only the time generating unit,and the facsimile-transmission-time setting register and the timecomparing unit may be provided separately from the RTC 324.

The UART 325 is a serial communication unit that functions as aninterface exchanging a control signal with the main control unit 309.The VIF 326 is a video interface that exchanges image data (imageinformation) with the main control unit 309. The BUSCNT 327 is a buscontrol circuit that connects or disconnects buses, and substitutes abit on a bus with another bit on the other bus. The DCR 328 is acompression/decompression circuit that compresses or decompresses theimage data. The memory 329 is a rewritable memory that is alwayssupplied with electricity from the main power source 310, and stores theimage data. The PORT 330 is an I/O (Input/Output) port that controlsinput and output of each signal by following an instruction from the CPU321. The FAX modem 331 modulates or demodulates image data for facsimilecommunication, which is received or to be transmitted.

The COMCNT 332 is a communication control circuit that is alwayssupplied with the electricity from the sub power source 311, andcontrols input and output of each signal by following an instructionfrom the CPU 321. In addition, the COMCNT 332 detects or receives a callsignal (a ringer signal) corresponding to a call out made by an externalfacsimile device, and notifies the CPU 321 about the call signal, if thecall signal is transmitted to the facsimile compound device from acommunication line. This COMCNT 332 starts carrying out energy-savingcontrol if the energy-saving mode is set. The COMCNT 332 can stilldetect the call signal from the communication line in the energy-savingmode.

The AFE 333 is an analog front end (an analog signal control circuit)that amplifies and filters a signal from the communication line (atelephone line). The DTMF 334 detects a DTMF signal, for example, acombination code of “*#0#” transmitted from an external device to thefacsimile compound device through the communication line.

The printer controller 304 converts print information transmitteddirectly from a personal computer (PC) 341 to the facsimile compounddevice, or print information transmitted from a personal computer to thefacsimile compound device via a LAN (Local Area Network) 342, to imagedata (image information). The scanner 305 reads a document image. Theplotter 306 forms or prints an image on a sheet of paper, based on imagedata converted by the printer controller 304, image data read by thescanner 305, or image data received by the FCU 303 and the like from anexternal facsimile device.

The personal interface 307 has a function similar to the personalinterface 18 according to the second embodiment except the power-supplycontrol means, where the personal interface 18 is previously describedwith reference to FIG. 21. The LADP 308 is a line adapter that has afunction similar to the data communication device 7 according to thesecond embodiment except the power-supply control means, where the datacommunication device 7 is previously described with reference to FIG.22.

The main control unit 309 controls the FCU 303, the printer controller304, the scanner 305, the plotter 306 and the personal interface 307collectively. The main power source 310 is a power source used forsupplying the electricity to each unit in the facsimile compound device.The sub power source 311 is a low-level power source different from themain power source 310. The power-supply control unit 312 is alwayssupplied with the electricity from the sub power source 311, and has afunction as power-supply control means possessed by each of the personalinterface 18, the main power source 61, the sub power source 62 and thedata communication device 7 according to the second embodiment, whichare previously described with reference to FIGS. 20, 21 and 22.

The facsimile compound device structured as described above hasfunctions that are almost same as those of the image-forming devices 1through 5 and the data communication device 7 according to the secondembodiment, and can acquire the same operation effect. In addition, in acase in which the facsimile compound device shifts to the energy-savingmode, the power-supply control unit 312 stops the power supply to adisplay device on the operation display unit that consumes muchelectricity, the printer controller 304, the scanner 305, the plotter306, and units other than the RTC 324, the COMCNT 332 and the memory 329in the FCU 303, by turning off the main power source 310. On the otherhand, the power-supply control unit 312 continues supplying theelectricity from the sub power source 311 to the CIG4 301 and the NCU302, in addition to the RTC 324, the COMCNT 332 and the memory 329included in the FCU 303.

In a case in which the COMCNT 332 of the FCU 303 receives a call signal(a ringer signal), which corresponds to a call out made by an externalfacsimile device and is transmitted from the communication line throughthe NCU 302, during the energy-saving mode, the COMCNT 332 notifies thepower-supply control unit 312, and, then, the CPU 321, about thereceived call signal.

After receiving the above-described notification from the COMCNT 332,the power-supply control unit 312 supplies the electricity from the mainpower source 310 to the entire FCU 303, in fact, a part that is notsupplied with the electricity regularly in the FCU 303, in addition tothe main control unit 309 and the plotter 306, by turning on the mainpower source 310.

In a case in which the CPU 321 receives the above-described notificationfrom the COMCNT 332 after being supplied with the electricity from themain power source 310, the CPU 321 outputs image data continuouslyreceived from the communication line by the NCU 302, to the plotter 306through a part in the FCU 303 related to communication and the maincontrol unit 309, every time after the NCU 302 receives a page of theimage data or all the pages of the image data. Meanwhile, the CPU 321instructs the plotter 306 to print the image data on a sheet of paper.When the plotter completes printing the image data on the sheet ofpaper, the CPU 321 instructs the power-supply control unit 312 to turnoff the main power source 310, thereby stopping the power supply to theparts that are supplied with the electricity according to thenotification from the COMCNT 332.

Additionally, in a case in which the facsimile compound device shifts tothe energy-saving mode while the facsimile-transmission time is set inthe facsimile-transsmission-time setting register of the RTC 324, thepower-supply control unit 312 stops the power supply to the displaydevice on the operation display unit, the printer controller 304, thescanner 305, the plotter 306, and the units in the FCU 303 other thanthe RTC 324, the COMCNT 332 and the memory in the FCU 303, by turningoff the main power source 310. On the other hand, thepower-supply-control unit 312 continues supplying the electricity fromthe sub power source 311 to the CIG4 301 and the NCU 302, in addition tothe RTC 324, the COMCNT 332 and the memory 329 included in the FCU 303.

Subsequently, the time comparing unit of the RTC 324 compares thecurrent time generated by the time generating unit with thefacsimile-transmission time preset in the facsimile-transmission-timesetting register during this energy-saving mode. The time comparing unitgenerates the facsimile-transmission request that requests for facsimiletransmission to the predetermined destination (the external facsimiledevice), if the current time matches with the facsimile-transsmissiontime, of if the current time passes the facsimile-transmission time.Subsequently, the time comparing unit supplies thefacsimile-transmission request to the power-supply control unit 312,and, then, the CPU 321.

After receiving the facsimile-transmission request from the timecomparing unit, the power-supply control unit 312 supplies theelectricity from the main power source 310 to the entire FCU 303, infact, the part that is not supplied with the electricity regularly, byturning on the main power source 310. Additionally, the CPU 321 of theFCU 303 transmits image data of a document initially read by the scanner305 and stored in the memory 329 to the predetermined destination byusing the FAX modem 331, the COMCNT 332 and the NCU 302, in a case inwhich the CPU 321 receives the facsimile-transsmission request from thetime comparing unit after being supplied with the electricity from themain power source 310.

In a case in which a document to be transmitted from the facsimilecompound device is set in the scanner 305, the power-supply control unit312 supplies the electricity from the main power source 310 to the maincontrol unit 309 and the scanner 305, in addition to the entire FCU 303,in fact, the part that is not supplied with the electricity regularly inthe FCU 303, by turning on the main power source 310.

After being supplied with the electricity from the main power source310, the scanner 305 reads image data of the document set therein, andoutputs the image data to the FCU 303 by use of the main control unit309. The CPU 321 of the FCU 303 transmits the image data to thepredetermined destination by use of the FAX modem 331, the COMCNT 332and the NCU 302, if the CPU 321 receives the image data from the scanner305 after being supplied with the electricity from the main power source310.

According to the third embodiment of the present invention, thefacsimile compound device used in the image-forming-device managementsystem can reduce unnecessary electricity consumption as well as cancarry out facsimile communication with an external facsimile deviceregularly.

A description will now be given of a facsimile compound device used inan image-forming-device management system according to a fourthembodiment of the present invention. FIG. 38 is a block diagram showinga structure of a main unit of the facsimile compound device used in theimage-forming-device management system according to the fourthembodiment. A unit shown in FIG. 38 corresponding to a unit shown inFIG. 37 has a same unit number as the unit shown in FIG. 37, and itsdescription is omitted in this embodiment.

The facsimile compound device shown in FIG. 38 includes the CIG4 301,the NCU 302, an FCU 350, the printer controller 304, the scanner 305,the plotter 306, the personal interface (PI) 307, the LADP 308, the maincontrol unit 309, the main power source 310, the sub power source 311and the power-supply control unit 312. In addition, the facsimilecompound device includes an operation display unit not shown in thefigures.

The FCU 350 is a facsimile control unit that controls communication withan external facsimile device or a central management device, andincludes the CPU 321, the ROM 322, the RAM 323, an LADP RAM 351, the RTC324, the UART 325, the VIF 326, the BUSCNT 327, the DCR 328, the memory329, the PORT 330, a FAX data modem 352, the COMCNT 332, the AFE 333,the DTMF 334, and the like. Units inside an area surrounded by a brokenline function as communication control means or a data communicationdevice.

The CPU 321 is a central processing unit that controls the entire FCU350 collectively by following a control program stored in the ROM 322,and functions as data-type deciding means, power-supply part settingmeans and power-supply part deciding means. The LADP RAM 351 is anon-volatile memory (data storing means) always supplied withelectricity from the sub power source 311, and stores data such as atotal counter value that is related to the facsimile compound device andshould be transmitted to the central management device.

The RTC 324 has a function as data-transmission request generating meansthat includes time generating means, and is always supplied with theelectricity from the sub power source 311. In detail, the RTC 44includes a time generating unit, a data-transmission-time settingregister, a data-transmission-time comparing unit, afacsimile-transmission-time setting register and afacsimile-transmission-time comparing unit. The time generating unitgenerates a current time (a year, a month, a date, an hour and aminute). The data-transmission-time setting register sets adata-transmission time, at which the facsimile compound device transmitsthe data related to the facsimile compound device to the centralmanagement device.

In addition, the data-transmission-time comparing unit compares thecurrent time generated by the time generating unit with thedata-transmission time preset in the data-transmission-time settingregister. The time comparing unit generates a data-transmission requestthat requests for data transmission to the central management device, ifthe current time and the data-transmission time match with each other,or if the current time passes the data-transmission time.

The facsimile-transmission-time setting register sets afacsimile-transmission time, at which the facsimile compound devicetransmits image data for facsimile communication to an externalfacsimile device. In addition, the facsimile-transmission-time comparingunit compares the current time generated by the time generating unitwith the facsimile-transmission time preset in thefacsimile-transmission-time setting register. Thefacsimile-transmission-time comparing unit generates afacsimile-transmission request that requests for facsimile transmissionto a predetermined destination (an external facsimile device), if thecurrent time and the facsimile-transmission time match with each other,or if the current time passes the facsimile-transmission time.

The RTC 324 may include only the time generating unit, and thedata-transmission-time setting register, the facsimile-transmission-timesetting register, the data-transmission-time comparing unit and thefacsimile-transmission-time comparing unit may be provided separatelyfrom the RTC 324.

The FAX data modem 352 modulates or demodulates communication datatransmitted or received between the facsimile compound device and thecentral management device, and image data for facsimile communication.This Fax data modem 352 functions as data transmitting means with theNCU 302 and the like.

The COMCNT 332 is a communication control circuit that is alwayssupplied with the electricity from the sub power source 311, andcontrols input and output of each signal by following an instructionfrom the CPU 321. In addition, a ringer-detecting unit included in theCOMCNT 332 detects or receives a call signal (a ringer signal)corresponding to a call out made by the central management device or anexternal facsimile device, and notifies the CPU 321 about the callsignal, if the call signal is transmitted to the facsimile compounddevice from a communication line. This COMCNT 332 shifts to carry outenergy-saving control if the energy-saving mode is set, in which theCOMCNT 332 can still detect the call signal from the communication line.

The main control unit 309 controls the FCU 350, the printer controller304, the scanner 305, the plotter 306 and the personal interface 307collectively. The power-supply control unit 312 is always supplied withthe electricity from the sub power source 311, and has a function aspower-supply control means and source (call-origin) deciding means.

When a main switch not shown in the figures is turned on, thepower-supply control unit 312 supplies electricity from the main powersource 310 to the entire facsimile compound device by turning on themain power source 310. The power-supply control unit 312 also suppliesthe electricity from the main power source 310 to a part necessary forprocessing a call signal by turning on the main power source 310, in acase in which the power-supply control unit 312 receives the call signalby use of the COMCNT 332 in the energy-saving mode.

Further, in a case in which the data-transmission request or thefacsimile-transmission request is generated by the RTC 324 during theenergy-saving mode, the power-supply control unit 312 supplies theelectricity from the main power source 310 to a part related tocommunication, including the NCU 302 and the FAX data modem 352, byturning on the main power source 310. The power-supply control unit 312also supplies the electricity from the main power source 310 to a partthat needs power-supply for acquiring data, which should be transmittedto the central management device, or image data, which should betransmitted to the external facsimile device, in the case in which thedata-transmission request or the facsimile-transmission request isgenerated.

Additionally, the power-supply control unit 312 stops supplying theelectricity from the main power source 310 to each of theabove-described units by turning off the main power source 310, aftercompletion of the data transmission to the central management device orthe facsimile transmission to the external facsimile device, or after afixed period such as an hour passes while the facsimile compound deviceis being unused. Additionally, the power-supply control unit also stopssupplying the electricity from that main power source 310 to each of theabove-described units in a case in which the main switch is turned off.

Functions of other units in the facsimile compound device according tothe fourth embodiment is the same as those of the facsimile compounddevice according to the third embodiment, and, thus, their descriptionsare omitted.

A description will now be given of a data communication process carriedout by the facsimile compound device according to the fourth embodiment.A description will initially be given of control including power-supplycontrol, which is performed by the facsimile compound device whenreceiving a call signal.

In a case in which the facsimile compound device shifts to theenergy-saving mode, the power-supply control unit 312 stops the powersupply to a display device on the operation display unit that consumesmuch electricity, the printer controller 304, the scanner 305, theplotter 306, and units other than the RTC 324, the COMCNT 332, thememory 329 and the LADP RAM 351 in the FCU 350, by turning off the mainpower source 310. On the other hand, the power-supply control unit 312continues supplying the electricity from the sub power source 311 to theCIG4 301 and the NCU 302, in addition to the RTC 324, the COMCNT 332,the memory 329 and the LADP RAM 351 included in the FCU 350.

In a case in which the call signal (a ringer signal) is transmitted froma communication line to the facsimile compound device according to acall out made by an external device, a ringer-detecting unit included inthe COMCNT 332 detects or receives the call signal through the NCU 302,and notifies the power-supply control unit 312 about the reception ofthe call signal. In a case in which the power-supply control unit 312receives the above-described notification from the COMCNT 332 during theenergy-saving mode, the power-supply control unit 312 supplies theelectricity from the main power source 310 to a part partially achievinga function as the source deciding means, which are the FAX data modem352, the AFE 333, the DTMF 334 and the PORT 330, by turning on the mainpower source 310.

The DTMF 334 notifies the power-supply control unit 312 about detectionof a DTMF signal, if the DTMF 334 detects the DTMF signal (an IT signal)supplied from the AFE 333 after being supplied with the electricity fromthe main power source 310. The power-supply control unit 312 decideswhether the source or the call-origin is the central management device,after supplying the electricity to the part partially achieving afunction as the source deciding means.

The power-supply control unit 312 decides that the source is a facsimiledevice, and supplies the electricity from the main power source 310 tothe main control unit 309, the plotter 306 and the entire FCU 350, infact, a part in the FCU 350 to which the electricity is not suppliedyet, in a case in which the DTMF 334 does not detect the DTMF signalafter the reception of the call signal. Subsequently, the power-supplycontrol unit 312 carries out facsimile-reception control as described inthe third embodiment.

On the other hand, in a case in which the DTMF 334 detects the DTMFsignal after the reception of the call signal, the power-supply controlunit 312 supplies the electricity from the main power source 310 to apart that is surrounded by the broken line in FIG. 38 and functions asthe communication control means (LADP), in fact, a unit included in thepart surrounded by the broken line, which is not supplied with theelectricity yet.

The CPU 321 carries out an initialization process not shown in thefigures after being supplied with the electricity from the main powersource 310 during the energy-saving mode. Additionally, the CPU 321decides a data type based on an instruction signal that is either thedata-transmission requesting signal or the data-write requesting signal,both being text data, in a case in which the CPU 321 receives theinstruction signal transmitted continuously after the DTMF signal fromthe central management device to the facsimile compound device by usingthe NCU 302, the COMCNT 332 and the FAX data modem 352.

In a case in which the CPU 321 recognizes that a process requested bythe central management device is data transmission to the centralmanagement device, based on a result of deciding the data type, the CPU321 transmits data stored in the LADP RAM 351 to the central managementdevice by use of the FAX data modem 352, the COMCNT 332 and the NCU 302.This data stored in the LADP RAM 351 is updated if necessary. Forexample, in a case in which the scanner 305 or the plotter 306 isactivated by being supplied with electricity, the CPU 321 acquires dataindicating an operation number such as a total counter number, andupdates the data stored in the LADP RAM 351 by using the acquiredoperation number.

In the above-described case in which the CPU 321 recognizes that theprocess requested by the central management device is data transmissionto the central management device, based on the result of deciding thedata type, the CPU 321 can also decide a part that needs power supplyfor acquiring data, which should be transmitted to the centralmanagement device among data related to the facsimile compound device,and can supply the electricity from the main power source 310 to thepart. Subsequently, the CPU 321 can acquire the data that should betransmitted to the central management device from the part, and cantransmit the data to the central management device by using the FAX datamodem 352, the COMCNT 332 and the NCU 302. For example, in a case inwhich the CPU 321 acquires data indicating the newest operation numberof the plotter 306, the CPU 321 also supplies the electricity from themain power source 310 to the plotter 306.

On the other hand, in a case in which the CPU 321 recognizes that theprocess requested by the central management device is a data-writeprocess, based on the result of deciding the data type, the CPU 321writes data such as parameters stored in a field of an informationrecord of the instruction signal (text data) received from the centralmanagement device, in the LADP RAM 351.

In the case in which the CPU 321 recognizes that the process requestedby the central management device is the data-write process, based on theresult of deciding the data type, the CPU 321 can decide a part otherthan the LADP RAM 351 that needs power supply for writing or rewritingdata, and can supply the electricity from the main power source 310 tothe part. Subsequently, the CPU 321 can write the data stored in thefield of the information record of the instruction signal (text data)received from the central management device, in the part. For example,in a case in which the CPU 321 rewrites a parameter of the plotter 306,the CPU 321 supplies the electricity from the main power source 310 tothe plotter 306.

After completion of the data transmission to the central managementdevice or the data-write process to the LADP RAM 351 or the like, theCPU 321 stops supplying the electricity from the main power source 310to each unit supplied with the electricity for carrying out the datatransmission or the data-write process, by turning off the main powersource 310.

A description will now be given of call control including power-supplycontrol carried out by the facsimile compound device according to thefourth embodiment.

When the facsimile compound device is in the energy-saving mode, thefacsimile-transmission-time comparing unit included in the RTC 324compares the current time generated by the time generating unit with thefacsimile-transmission time preset in the facsimile-transsmission-timesetting register. If the current time matches with thefacsimile-transmission time, or if the current time passes thefacsimile-transmission time, the facsimile-transmission-time comparingunit generates the facsimile-transmission request that requests forfacsimile transmission to the predetermined destination which is anexternal facsimile device, and supplies the facsimile-transmissionrequest to the power-supply control unit 312, and, then, to the CPU 321.Facsimile-transsmission control following the above-described generationof the facsimile-transmission request is described in the thirdembodiment.

On the other hand, during the energy-saving mode, thedata-transmission-time comparing unit included in the RTC 324 comparesthe current time generated by the time generating unit with thedata-transmission time preset in the data-transmission-time settingregister. If the current time matches with the data-transmission time,or if the current time passes the data-transmission time, thedata-transmission-time comparing unit generates the data-transmissionrequest that requests for data transmission to the central managementdevice, and supplies the data-transmission request to the power-supplycontrol unit 312, and, then, to the CPU 321.

After receiving the data-transmission request, the power-supply controlunit 312 supplies the electricity from the main power source 310 to thepart surrounded by the broken line in FIG. 38, which functions as thecommunication control means (LADP), by turning on the main power source310. The CPU 321 carries out the initialization process not shown in thefigures after being supplied with the electricity from the main powersource 310 during the energy-saving mode. Subsequently, the CPU 321transmits the data stored in the LADP RAM 351 to the central managementdevice by using the FAX data modem 352, the COMCNT 332 and the NCU 302,if receiving the data-transmission request from the RTC 324. The CPU 321stops supplying the electricity to the part surrounded by the brokenline shown in FIG. 38 by using the power-supply control unit 312, aftercompleting the data transmission to the central management device.

Alternatively, the CPU 321 decides whether the memory 329 stores imagedata. In a case in which the CPU 321 decides that the memory 329 storesthe image data, the CPU 321 can set a facsimile-transmission timecorresponding to the image data in the facsimile-transsmission-timesetting register. Subsequently, the facsimile-transmission-timecomparing unit compares the current time with the facsimile-transmissiontime corresponding to the image data. If the current time matches withthe facsimile-transmission time, or if the current time passes thefacsimile-transmission time, the facsimile-transmission-time comparingunit may generate the facsimile-transmission request that requests fortransmission of the image data to an external facsimile device.

After transmitting the image data corresponding to thefacsimile-transmission time set in the facsimile-transmission-timesetting register to the external facsimile device (the predetermineddestination) at the facsimile-transmission time, the CPU 321 decideswhether the memory 329 stores another image data. If the CPU 321 decidesthat the memory 329 stores another image data, the CPU 321 sets afacsimile-transsmission time for the image data in thefacsimile-transsmission-time setting register.

Additionally, if the external facsimile device is busy when thefacsimile compound device calls out the external facsimile device onceaccording to the generation of the facsimile-transmission request, thefacsimile compound device cannot carry out facsimile transmission. Thus,the facsimile compound device calls out the external facsimile deviceagain. By setting a next facsimile-transmission time (a re-call time)for re-calling out the external facsimile device in thefacsimile-transmission-time setting register, the facsimile compounddevice can control the main power source 310 in detail.

The CPU 321 may also decide whether the LADP RAM 351 stores data. In acase in which the CPU 321 decides that the LADP RAM 351 stores the data,the CPU 321 can set a data-transmission time corresponding to the datain the data-transmission-time setting register. Subsequently, thedata-transmission-time comparing unit compares the current time with thedata-transmission time corresponding to the data. If the current timematches with the data-transmission time, or if the current time passesthe data-transmission time, the data-transmission-time comparing unitmay generate the data-transmission request that requests fortransmission of the data to the central management device.

After transmitting the data corresponding to the data-transmission timeset in the data-transmission-time setting register to the centralmanagement device at the data-transmission time, the CPU 321 decideswhether the LADP RAM 351 stores another data. If the CPU 321 decidesthat the LADP RAM 351 stores another data, the CPU 321 sets adata-transmission time for the data in the data-transmission-timesetting register.

Additionally, if the central management device is busy when thefacsimile compound device calls out the central management device onceaccording to the generation of the data-transmission request, thefacsimile compound device cannot carry out data transmission. Thus, thefacsimile compound device calls out the central management device again.By setting a next data-transmission time (a re-call time) for recallingout the central management device in the data-transmission-time settingregister, the facsimile compound device can control the main powersource 310 in detail.

A description will now be given of a power-supply control process and apower-supply part setting process carried out by the CPU 321 of thefacsimile compound device, with reference to FIGS. 27 through 34.

The CPU 321 carries out a power-supply control process as follows, forexample. The CPU 321 supplies electricity from the main power source 310to a part that needs power supply for acquiring data, which should betransmitted to the central management device, or a part that needs thepower supply for writing data, in a case in which the CPU 321 receivesan instruction signal from the central management device. Thisinstruction signal is either the data-transmission requesting signal orthe data-write requesting signal.

The CPU 321 needs to set the part that needs the power supply in orderto carry out the above-described power-supply control process. Controlfor setting the part that needs the power-supply includes the followingcontrols K1 and K2.

(K1) The CPU 321 of the facsimile compound device sets the part thatneeds the power supply based on an operation signal outputted from theoperation display unit in accordance with a key operation.

(K2) The CPU 321 sets the part that needs the power supply in accordancewith a type of data added to the instruction signal (text data)transmitted from the central management device to the facsimile compounddevice.

A simple description will initially be given of the control K1 forsetting the part that needs the power supply, since the control K1 isthe same as the control I1 described in the second embodiment.

In the normal operation mode, the CPU 321 of the facsimile compounddevice sets the SP mode, by a key operation on the operation displayunit. Additionally, the CPU 321 displays a power-supply mode settingscreen on a text-display unit of the operation display unit by a fixedkey operation, as shown in FIG. 28. The CPU 321 sets a unitcorresponding to a key indicated as “ON”on the text-display unit, to apart that needs the power supply, and sets a unit corresponding to a keyindicated as “OFF”, to a part that does not need the power supply, bycarrying the operation described in the second embodiment.

Accordingly, in the case in which the power-supply control unit 312 ofthe facsimile compound device receives the instruction signal from thecentral management device, the power-supply control unit 312 suppliesthe electricity from the main power source 310 to the part including theCPU 321, which is surrounded by the broken line in FIG. 38 and functionsas the communication control means, and the unit preset as the part thatneeds the power supply, by turning on the main power source 310.Meanwhile, the power-supply control unit 312 continues not supplying theelectricity to units other than the above-described part and unit. Thispower-supply control is the same as the power-supply control describedin the second embodiment, and, thus, its description is omitted here.

Next, a simple description will be given of the control K2 for settingthe part that needs the power supply, since the control K2 is the sameas the control I2 described in the second embodiment.

The power-supply control unit 312 of the facsimile compound devicesupplies the electricity from the main power source 310 to the partsurrounded by the broken line in FIG. 38, by turning on the main powersource 310, in a case in which the power-supply control unit 312receives the fixing-temperature requesting signal shown in FIG. 30 fromthe central management device. Additionally, the power-supply controlunit 312 controls the main power source 310 according to bits “0” and“1” inside the power-source control information by extracting andanalyzing the power-source control information from thefixing-temperature requesting signal. For example, if a bitcorresponding to a fixing unit included in the plotter 306 is “1”, thepower-supply control unit 312 recognizes that the fixing unit is set tothe part that needs the power supply, and, then, operates a relay toclose a switch as shown in FIG. 25, thereby supplying the electricityfrom the main power source 310 to the fixing unit. Accordingly, the CPU321 of the facsimile compound device can acquire a set value of a fixingtemperature from the fixing unit.

As described above, the facsimile compound device used in theimage-forming-device management system according to the fourthembodiment includes the NCU 302, the power-supply control unit 312, theRTC 324, the memory 329, the COMCNT 332 and the LADP RAM 351, which arealways provided with the electricity from the sub power source 311. Inthe energy-saving mode, the power-supply control unit 312 supplies theelectricity from the main power source 310 to the parts that partiallyfunction as the source detecting means, which are the FAX data modem352, the AFE 333, the DTMF 334 and the PORT 330, in the case in whichthe ringer detecting unit included in the COMCNT 332 detects a callsignal that corresponds to a call out made by an external device and istransmitted to the facsimile compound device through the NCU 302 from acommunication line. The power-supply control unit 312 decides whetherthe source (the call origin) is the central management device, based ona result of detecting the DTMF signal by the DTMF 324 after thedetection of the call signal.

In the case in which the power-supply control unit 312 decides that thesource is the central management device in accordance with the detectionof the DTMF signal by the DTMF 324, the power-supply control unit 312supplies the electricity from the main power source 310 to the units notsupplied with the electricity yet inside the part that functions as thecommunication control means and is surrounded by the broken line in FIG.38.

Subsequently, the CPU 321 receives the instruction signal (text data)transmitted continuously after the DTMF signal from the centralmanagement device, through the NCU 302, the COMCNT 332 and the FAX datamodem 352, and, then communicates with the central management device.For example, the CPU 321 transmits data stored in the LADP RAM 351 tothe central management device by using the FAX data modem 352, theCOMCNT 332 and the NCU 302. After completion of the data transmission tothe central management device, the power-supply control unit 312 turnsoff the main power source 310, thereby stopping the power supply to eachpart related to communication.

Accordingly, the facsimile compound device can reduce unnecessaryelectricity consumption as well as can carry out communication betweenthe facsimile compound device and the central management device.

Additionally, in the case in which the CPU 321 receives the instructionsignal, which is the data-transmission requesting signal or thedata-write requesting signal, from the central management device, theCPU 321 instructs the power-supply control unit 312 to supply theelectricity from the main power source 310 to a predetermined part. Thispredetermined part is either the part that needs power supply foracquiring data, which should be transmitted to the central managementdevice, or the part that needs the power supply for writing datareceived from the central management device. Subsequently, the CPU 321stops the power supply after completing communication with the centralmanagement device. Accordingly, the facsimile compound device can reduceits electricity consumption. Additionally, the central management devicecan definitely acquire desired data from the facsimile compound device.

Alternatively, in the case in which the CPU 321 receives the instructionsignal, which is the data-transmission requesting signal or thedata-write requesting signal, from the central management device, theCPU 321 decides a type of data that should be transmitted to the centralmanagement device, based on the instruction signal. Subsequently, theCPU 321 decides the part that needs power supply for acquiring data,which should be transmitted to the central management device, or thepart that needs the power supply for writing data received from thecentral management device, based on a result of deciding a type of thedata. The CPU 321, then, instructs the power-supply control unit 312 tosupply the electricity from the main power source 310 to the part thatneeds the power supply. After completing communication with the centralmanagement device, the CPU 321 stops the power supply from the mainpower source 310. Accordingly, the facsimile compound device can reduceits electricity consumption. Additionally, the central management devicecan definitely acquire desired data from the facsimile compound device.

The sub power source 311 may constantly supply the electricity to theNCU 302, the power-supply control unit 312, the RTC 324, the memory 329,the PORT 330, the COMCNT 332, the AFE 333, the DTMF 334, the LADP RAM351 and the FAX data modem 352. In the case in which theringer-detecting unit of the COMCNT 332 detects a call signal thatcorresponds to a call out made by an external device and is transmittedfrom the communication line to the facsimile compound device through theNCU 302, the DTMF 324 checks if the DTMF signal is received through theNCU 302, right after the detection of the call signal by the COMCNT 332.Accordingly, the power-supply control unit 312 can decide whether thesource (the call origin) is the central management device according to aresult of detecting the DTMF signal by the DTMF 324.

Furthermore, the facsimile compound device used in theimage-forming-device management system according to the fourthembodiment includes the NCU 302, the power-supply control unit 312, theRTC 324, the memory 329, the COMCNT 332 and the LADP RAM 351, which areconstantly supplied with the electricity from the sub power source 311.In the energy-saving mode, the data-transmission-time comparing unitincluded in the RTC 324 compares the current time generated by the timegenerating unit with the data-transmission time preset in thedata-transmission-time setting register. This data-transmission-timecomparing unit generates the data-transmission request that requests fordata transmission to the central management device, if the current timematches with the data-transmission time, or if the current time passesthe data-transmission time.

If the power-supply control unit 312 is notified about the generation ofthe data-transmission request, the power-supply control unit 312supplies the electricity from the main power source 310 to the part thatfunctions as the communication control means (LADP) and is surrounded bythe broken line in FIG. 38, by turning on the main power source 310.Consequently, the CPU 321 transmits data stored in the LADP RAM 351 tothe central management device by using the FAX data modem 352, theCOMCNT 332 and the NCU 302. After the data transmission to the centralmanagement device, the CPU 321 stops the power supply to the partsurrounded by the broken line in FIG. 38, by turning off the main powersource 310 by use of the power-supply control unit 312.

Accordingly, the facsimile compound device can reduce unnecessaryelectricity consumption as well as can carry out data transmission tothe central management device at any time.

In the above-described embodiments, an operation mode of each device canbe selected between the normal operation mode and the energy-savingmode. However, the operation mode may always be set to the energy-savingmode, in which a main power source is normally turned off.

The embodiments have been described about the data communication deviceand the image-forming device such as a copy machine and a facsimilecompound device used in a remote management system, which is theimage-forming-device management system for managing the image-formingdevice remotely. However, the present invention is not limited to theabove-described embodiments, and is applicable to a data communicationdevice used in a remote management system that remotely manages varioustypes of remotely-managed devices such as a key-card device managing thenumber of copies made by a copy machine by a group, a gas meter, anelectricity meter and a vending machine.

As described above, the data communication device and the image-formingdevice that compose the image-forming-device management system canreduce unnecessary electricity consumption as well as can carry our datatransmission at any time.

The above description is provided in order to enable any person skilledin the art to make and use the invention and sets forth the best modecontemplated by the inventors of carrying out the invention.

The present invention is not limited to the specially disclosedembodiments and variations, and modifications may be made withoutdeparting from the scope and spirit of the invention.

The present application is based on Japanese Priority Applications No.2000-172219, filed on Jun. 8, 2000 No. 2000-196899, filed on Jun. 29,2000, and No. 2001-051180, filed on Feb. 26, 2001, the entire contentsof which are hereby incorporated by reference.

1. A data communication device that is connected to a central managementdevice through a communication line, and controls communication betweensaid central management device and an image-forming device, said datacommunication device comprising: a power source; a data-storing unitstoring data related to said image-forming device; a data transmissionunit; a transmission-request generating unit being always supplied withelectricity from said power source, and generating a transmissionrequest that requests for transmission of the data to said centralmanagement device; and a power-supply control unit being always suppliedwith the electricity from said power source, and supplying theelectricity from said power source to a communication-related partincluding said data transmission unit, if said transmission-requestgenerating unit generates the transmission request, wherein said datatransmission unit transmits the data to said control management deviceif being supplied with the electricity from said power source.
 2. Thedata communication device as claimed in claim 1, wherein saidpower-supply control unit stops supplying the electricity from saidpower source to said communication-related part, after said datatransmission unit completes transmitting the data related to saidimage-forming device to said central management device.
 3. The datacommunication device as claimed in claim 1, wherein saidtransmission-request generating unit includes: a time generating unitgenerating a current time; and a time comparing unit comparing thecurrent time with a predetermined data-transmission time, and generatingthe transmission request if deciding that the current time matches withthe data-transmission time.
 4. The data communication device as claimedin claim 1, wherein said transmission-request generating unit includes:a time generating unit generating a current time; a data deciding unitcomparing the current time with a predetermined data-transmission time,and deciding whether the data related to said image-forming device isstored in said data-storing unit if deciding that current time matcheswith the data-transmission time; and a transmission requesting unitgenerating the transmission request if said data deciding unit decidesthat the data related to said image-forming device is stored in saiddata-storing unit.
 5. The data communication device as claimed in claim1, wherein said transmission-request generating unit includes: a timegenerating unit generating a current time; a data deciding unit decidingwhether the data related to said image-forming device is stored in saiddata-storing unit; and a time comparing unit comparing the current timewith a predetermined data-transmission time corresponding to the datarelated to said image-forming device if said data deciding unit decidesthat the data related to said image-forming device is stored in saiddata-storing unit, and generating the transmission request if decidingthat the current time matches with the data-transmission time.
 6. Thedata communication device as claimed in claim 1, wherein saidtransmission-request generating unit includes: a time generating unitgenerating a current time; a data deciding unit deciding whether thedata related to said image-forming device is stored in said data-storingunit; a time setting unit setting a transmission time corresponding tothe data related to said image-forming device, if said data decidingunit decides that the data related to said image-forming device isstored in said data-storing unit; and a time comparing unit comparingthe current time with the transmission time, and generating thetransmission request if deciding that the current time matches with thetransmission time.
 7. The data communication device as claimed in claim1, further comprising a call-origin deciding unit being always suppliedwith the electricity from said power source, and deciding whether a callorigin is said central management device based on a signal receivedcontinuously after a call signal, if receiving the call signal from saidcommunication line in accordance with a call out made by the callorigin, wherein said power-supply control unit is always supplied withthe electricity from said power source, and supplies the electricityfrom said power source to said communication-related part if saidcall-origin deciding unit decides that the call origin is said centralmanagement device, and wherein said data transmission unit transmits thedata related to said image-forming device to said control managementdevice if being supplied with the electricity from said power source. 8.The data communication device as claimed in claim 7, wherein saidpower-supply control unit stops supplying the electricity from saidpower source to said communication-related part, after said datatransmission unit completes transmitting the data related to saidimage-forming device to said central management device.
 9. The datacommunication device as claimed in claim 1, further comprising: atransmission-request-signal transmitting unit; a data writing unit; andan acquisition-request generating unit being always supplied withelectricity from said power source, and generating an acquisitionrequest that requests for acquisition of the data related to saidimage-forming device from said image-forming device, wherein saidpower-supply control unit supplies the electricity from said powersource to said transmission-request-signal transmitting unit and saiddata writing unit if said acquisition-request generating unit generatesthe acquisition request, said transmission-request-signal transmittingunit transmits a transmission-request signal to said image-formingdevice if being supplied with the electricity from said power source,and said data writing unit writes the data related to said image-formingdevice in said data-storing unit if receiving the data related to saidimage-forming device from said image-forming device in response to saidtransmission-request signal after being supplied with the electricityfrom said power source.
 10. The data communication device as claimed inclaim 9, wherein said power-supply control unit stops supplying theelectricity from said power source to said transmission-request-signaltransmitting unit and said data writing unit, after said data writingunit completes writing the data related to said image-forming device insaid data-storing unit.
 11. The data communication device as claimed inclaim 9, wherein said acquisition-request generating unit includes: atime generating unit generating a current time; and a time comparingunit comparing the current time with a predetermined data-acquisitiontime, and generating the acquisition request if deciding that thecurrent time matches with the data-acquisition time.
 12. The datacommunication device as claimed in claim 7, further comprising: adata-type deciding unit; and a transmission-request-signal transmittingunit, wherein said power-supply control unit supplies the electricityfrom said power source to said data-type deciding unit and saidtransmission-request-signal transmitting unit if said call-origindeciding unit decides that the call origin is the central managementdevice, wherein said data-type deciding unit decides a type of data thatshould be transmitted to said central management device based on saidsignal received continuously after the call signal from saidcommunication line, after being supplied with the electricity from saidpower source, wherein said transmission-request-signal transmitting unittransmits a transmission-request signal to said image-forming device, ifand only if said transmission-request-signal transmitting unit issupplied with the electricity from said power source, and said data-typedeciding unit decides that said data which should be transmitted to saidcentral management device is the data related to said image-formingdevice, and wherein said data transmission unit transmits the datarelated to said image-forming device, to said central management device,if and only if being supplied with the electricity from said powersource and receiving said data related to said image-forming device fromsaid image-forming device in response to the transmission-requestsignal.
 13. The data communication device as claimed in claim 12,wherein said transmission-request-signal transmitting unit addsinformation indicating said type decided by said data-type decidingunit, to the transmission-request signal.
 14. The data communicationdevice as claimed in claim 1, further comprising a data writing unit,wherein said power-supply control unit supplies the electricity fromsaid power source if receiving a startup signal starting up said datacommunication device from said image-forming device, and said datawriting unit writes the data related to said image-forming device insaid data-storing unit if being supplied with the electricity from saidpower source and receiving the data related to said image-forming devicefrom said image-forming device.
 15. The data communication device asclaimed in claim 14, wherein said power-supply control unit stopssupplying the electricity from said power source to said data writingunit after said data writing unit completes writing the data related tosaid image-forming device in said data-storing unit.
 16. The datacommunication device as claimed in claim 14, further comprising adata-type deciding unit, wherein said power-supply control unit suppliesthe electricity from said power source to said data-type deciding unitif receiving the startup signal from said image-forming device, saiddata-type deciding unit decides a type of the data related to saidimage-forming device if receiving the data related to said image-formingdevice from said image-forming device after being supplied with theelectricity from said image-forming device, said power-supply controlunit supplies the electricity from said power source to saidcommunication-related part if said data-type deciding unit decides thatthe data received from said image-forming device is data indicating anabnormal condition, and said data transmission unit transmits the datareceived from said image-forming device to said data communicationdevice if receiving the electricity from the power source.
 17. The datacommunication device as-claimed in claim 1, wherein said communicationline is a public line, and said image-forming device is a copy machine.18. An image-forming device that is connected to a data communicationdevice, and communicates with a central management device in accordancewith control carried out by said data communication device, saidimage-forming device comprising: a power source; a data transmissionunit; and a power-supply control unit being always supplied withelectricity from said power source, and supplying the electricity fromsaid power source to a communication-related part including said datatransmission unit if receiving a transmission-request signal from saiddata communication device, wherein said data transmission unit transmitsdata related to said image-forming device, to said data communicationdevice if being supplied with the electricity from said power source.19. The image-forming device as claimed in claim 18, wherein said datarelated to said image-forming device is data that indicates a totalnumber of images formed by said image-forming device or a condition ofsaid image-forming device.
 20. The image-forming device as claimed inclaim 18, wherein said power-supply control unit stops supplying theelectricity from said power source to said communication-related part,after said data transmission unit completes transmitting the datarelated to said image-forming device, to said data communication device.21. The image-forming device as claimed in claim 18, wherein saidpower-supply control unit supplies the electricity from said powersource to a part that needs power supply for acquiring data, whichshould be transmitted to said central management device among the datarelated to said image-forming device, if receiving thetransmission-request signal from said data communication device.
 22. Theimage-forming device as claimed in claim 21, wherein said power-supplycontrol unit stops supplying the electricity from said power source tosaid part that needs the power supply for acquiring the data, whichshould be transmitted to said central management device, after said datatransmission unit completes transmitting the data that should betransmitted to said central management device, to said datacommunication device.
 23. The image-forming device as claimed in claim21, further comprising a power-supply part setting unit setting the partthat needs the power supply for acquiring the data, which should betransmitted to said central management device.
 24. The image-formingdevice as claimed in claim 18, wherein said data transmission unittransmits data corresponding to information that indicates a type ofdata, which should be transmitted to said central management device, andis added to said transmission request signal, among the data related tosaid image-forming device, if said data transmission unit is suppliedwith the electricity from said power source.
 25. The image-formingdevice as claimed in claim 24, wherein said power-supply control unitstops supplying the electricity from said power source to saidcommunication-related part, after said data transmission unit completestransmitting the data corresponding to the information, to said datacommunication device.
 26. The image-forming device-as claimed in claim24, wherein said power-supply control unit decides the part that needsthe power supply for acquiring the data, which should be transmitted tosaid central management device, based on said information added to thetransmission-request signal, and supplies the electricity from saidpower source to the part that needs the power supply for acquiring thedata, which should be transmitted to said central management device, ifreceiving the said data-transmission signal from said data communicationdevice.
 27. The image-forming device as claimed in claim 26, whereinsaid power-supply control unit stops supplying the electricity from saidmain power source to said part that needs the power supply for acquiringthe data, which should be transmitted to said central management device,after said data transmission unit completes transmitting the datacorresponding to the information to said data communication device. 28.The image-forming device as claimed in claim 18, further comprising: astartup-signal transmitting unit; and a main switch, wherein saidpower-supply control unit is always supplied with the electricity fromsaid power source, and supplies the electricity from said power sourceto said image-forming device entirely according to an operation of saidmain switch, wherein said startup-signal transmitting unit transmits astartup signal to said data communication device to start up said datacommunication device if being supplied with the electricity from saidpower source, and wherein said data transmission unit transmits the datarelated to said image-forming device, to said data communication deviceafter said data transmission unit is supplied with the electricity fromsaid power source, and said startup-signal transmitting unit transmitsthe startup signal to said data communication device.
 29. Theimage-forming device as claimed in claim 18, further comprising: astartup-signal transmitting unit; and a transmission-request generatingunit, wherein said communication-related part further includes saidstartup-signal transmitting unit, wherein said transmission-requestgenerating unit is always supplied with the electricity from said powersource, and generates a transmission request that requests fortransmission of the data related to said image-forming device to saiddata communication device, wherein said power-supply control unit isalways supplied with the electricity from said power source, andsupplies the electricity from said power source to saidcommunication-related part if said transmission-request generating unitgenerates the transmission request, wherein said startup-signaltransmitting unit transmits a startup signal to said data communicationdevice to start up said data communication device if being supplied withthe electricity from said power source, and wherein said datatransmission unit transmits the data related to said image-formingdevice, to said data communication device after said data transmissionunit is supplied with the electricity from said power source, and saidstartup-signal transmitting unit transmits the startup signal to saiddata communication device.
 30. The image-forming device as claimed inclaim 29, wherein said power-supply control unit stops supplying theelectricity from said power source to said communication-related part,after said data transmission unit completes transmitting the datarelated to said image-forming device to said data communication device.31. The image-forming device as claimed in claim 29, wherein saidpower-supply control unit supplies the electricity from said powersource to a part that needs power supply for acquiring data, whichshould be transmitted to said central management device among the datarelated to said image-forming device, if said transmission-requestgenerating unit generates the transmission request.
 32. Theimage-forming device as claimed in claim 31, wherein said power supplycontrol unit stops supplying the electricity from said power source tosaid part that needs the power supply for acquiring the data, whichshould be transmitted to said central management device, after said datatransmission unit completes transmitting the data that should betransmitted to said central management device, to said datacommunication device.
 33. The image-forming device as claimed in claim31, further comprising a power-supply part setting unit setting the partthat needs the power supply for acquiring the data, which should betransmitted to said central management device.
 34. An image-formingdevice that is connected to a central management device through acommunication line, comprising: a power source; a communication controlunit controlling communication with said central management device; atransmission-request generating unit being always supplied withelectricity from said power source, and generating a transmissionrequest that requests for data transmission to said central managementdevice; and a power-supply control unit being always supplied with theelectricity from said power source, and supplying the electricity fromsaid power source to said communication control unit if saidtransmission request generating unit generates the transmission request,wherein said communication control unit transmits data related to saidimage-forming device to said central management device, if beingsupplied with the electricity from said power source.
 35. Theimage-forming device as claimed in claim 34, wherein said centralmanagement device is an external device, and said communication line isa public line.
 36. The image-forming device as claimed in claim 34,wherein said data related to said image-forming device is data thatindicates a total number of images formed by said image-forming deviceor a condition of said image-forming device.
 37. The image-formingdevice as claimed in claim 34, wherein said power-supply control unitstops supplying the electricity from said power source to saidcommunication control unit, after said communication control unitcompletes transmitting the data related to said image-forming device tosaid central management device.
 38. The image-forming device as claimedin claim 34, wherein said transmission-request generating unit includes:a time generating unit generating a current time; and a time comparingunit comparing the current time with a predetermined data-transmissiontime, and generating the transmission request if deciding that thecurrent time matches with the data-transmission time.
 39. Theimage-forming device as claimed in claim 34, further comprising acall-origin deciding unit being always supplied with the electricityfrom said power source, and deciding whether a call origin is saidcentral management device based on a signal received continuously aftera call signal, if receiving the call signal from said communication linein accordance with a call out made by the call origin, wherein saidpower-supply control unit is always supplied with the electricity fromsaid power source, and supplies the electricity from said power sourceto said communication control unit if said call-origin deciding unitdecides that the call origin is said central management device, andwherein said communication control unit transmits the data related tosaid image-forming device to said control management device if beingsupplied with the electricity from said power source.
 40. Theimage-forming device as claimed in claim 35, wherein said power-supplycontrol unit stops supplying the electricity from said power source tosaid communication control unit, after said communication control unitcompletes transmitting the data related to said image-forming device tosaid central management device.
 41. The image-forming device as claimedin claim 39, wherein said power-supply control unit supplies theelectricity from said power source to a part that needs power supply foracquiring data, which should be transmitted to said central managementdevice among the data related to said image-forming device, if saidcall-origin deciding unit decides that the call origin is said centralmanagement device.
 42. The image-forming device as claimed in claim 41,wherein said power-supply control unit stops supplying the electricityfrom said power source to said part that needs the power supply foracquiring the data, which should be transmitted to said centralmanagement device, after said communication control unit completestransmitting the data that should be transmitted to said centralmanagement device, to said central management device.
 43. Theimage-forming device as claimed in claim 41, further comprising apower-supply part setting unit setting the part that needs the powersupply for acquiring the data, which should be transmitted to saidcentral management device.
 44. The-image-forming device as claimed inclaim 39, further comprising: a data-type deciding unit being suppliedwith the electricity from said power source, and deciding a type of datathat should be transmitted to said central management device based onthe signal received continuously after the call signal from saidcommunication line, if said call-origin deciding unit decides that thecall origin is said central management device; and a power-supply partdeciding unit being always supplied with the electricity from said powersource, and deciding a part that needs power supply for acquiring data,which should be transmitted to said central management device among thedata related to said image-forming device, wherein said power-supplycontrol unit supplies the electricity from said power source to a partdecided by said power-supply part deciding unit as the part that needspower supply for acquiring data, which should be transmitted to saidcentral management device, and wherein said communication control unitacquires the data that should be transmitted to said central managementdevice, and transmits the data that should be transmitted to saidcentral management device, to said central management device, if beingsupplied with the electricity from said power source.
 45. Theimage-forming device as claimed in claim 44, wherein said power-supplycontrol unit stops supplying the electricity from said power source tosaid communication control unit and said part decided by saidpower-supply part deciding unit as the part that needs power supply foracquiring data, which should be transmitted to said central managementdevice, if said communication control unit completes transmitting thedata that should be transmitted to said central management device, tosaid central management device.
 46. An image-forming-device managementsystem, comprising: an image-forming device; a data communicationdevice; and a central management device managing saidimage-forming-device remotely through a communication line and said datacommunication device, wherein said data communication device includes: afirst power source; a data-storing unit storing data of saidimage-forming device; a data-type deciding unit; atransmission-request-signal transmitting unit; a first data transmissionunit; a call-origin deciding unit being always supplied with theelectricity from said first power source, and deciding whether a callorigin is said central management device based on a signal receivedcontinuously after a call signal if receiving the call signal from saidcommunication line in accordance with a call out made by the callorigin; and a first power-supply control unit being always supplied withthe electricity from said first power source, and supplying theelectricity from said first power source to said data-type decidingunit, said transmission-request-signal transmitting unit and said fistdata transmission unit, if said call-origin deciding unit decides thatthe call origin is said central management device, wherein saiddata-type deciding unit decides a type of data that should betransmitted to said central management device based on the signalreceived continuously after the call signal from said communicationline, if being supplied with the electricity from said first powersource, wherein said transmission-request-signal transmitting unittransmits a transmission-request signal to said image-forming device, ifand only if said transmission-request-signal transmitting unit issupplied with the electricity from said first power source, and saiddata-type deciding unit decides that the data which should betransmitted to said central management device is the data related tosaid image-forming device, wherein said first data transmission unittransmits the data related to said image-forming device to said centralmanagement device if being supplied with the electricity from said firstpower source, and receiving the data related to said image-formingdevice from said image-forming device in response to thetransmission-request signal transmitted to said image-forming device bythe transmission-request-signal transmitting unit, and wherein saidfirst power-supply control unit stops supplying the electricity fromsaid first power source to said data-type deciding unit, saidtransmission-request-signal transmitting unit and said first datatransmission unit, after said first data transmission unit completestransmitting the data related to said image-forming device to saidcentral management device, wherein said image-forming device includes: asecond power source; a second data transmission unit; and a secondpower-supply control unit that is always supplied with the electricityfrom said second power source, and supplies the electricity from saidsecond power source to a communication-related part including saidsecond data transmission unit if receiving the transmission-requestsignal from said data communication device, wherein said second datatransmission unit transmits the data related to said image-formingdevice, to said data communication device if being supplied with theelectricity from said second power source, and wherein said secondpower-supply control unit stops supplying the electricity from saidsecond power source to said communication-related part after said seconddata transmission unit completes transmitting the data related to saidimage-forming device to said data communication device.
 47. Theimage-forming-device management system as claimed in claim 46, whereinsaid transmission-request-signal transmitting unit of the datacommunication device adds information indicating the type of the datathat should be transmitted to said central management device, to thetransmission-request signal, said type being decided by said data-typedeciding unit, and wherein said second power-supply control unit of theimage-forming device decides a part that needs power supply foracquiring data that should be transmitted to said central managementdevice based on said information added to the transmission-requestsignal if receiving the transmission-request signal from said datacommunication device, and supplies the electricity from said secondpower source to a part decided by said second power-supply control unitas the part that needs power supply for acquiring the data that shouldbe transmitted to said central management device, and stops supplyingthe electricity from said second power source to said part decided bysaid second power-supply control unit as the part that needs powersupply for acquiring the data that should be transmitted to said centralmanagement device, after said second data transmission unit completestransmitting the data that should be transmitted to said centralmanagement device, to said data communication device.
 48. Theimage-forming-device management system as claimed in claim 46, whereinsaid data related to said image-forming device is data that indicates atotal number of images formed by said image-forming device or acondition of said image-forming device.
 49. A method of controllingpower supply in an image-forming-device management system that remotelymanages an image-forming device by using a central management devicethrough a communication line and a data communication device, saidmethod comprising the steps of: supplying electricity constantly from apower source of said data communication device to call-signal receivingmeans for receiving a call signal from the communication line accordingto a call out made by a call origin, and call-origin deciding means fordeciding whether the call origin is said central management device whenreceiving the call signal by the call-signal receiving means; supplyingthe electricity from the power source of said data communication deviceto a communication-related part if deciding that the call origin is saidcentral management device by said call-origin deciding means, saidcommunication-related part including data-type deciding means fordeciding a type of data that should be transmitted to said centralmanagement device based on a signal received continuously after the callsignal from said communication line, transmission-request signaltransmitting means for transmitting a transmission request signal addedwith information indicating the type of the data that should betransmitted to said central management device, said type being decidedby said data-type deciding means, to said image-forming device ifrecognizing that the data which should be transmitted to said centralmanagement device is data related to said image-forming device based ona result of deciding the type of the data that should be transmitted tosaid central management device, and data transmission means forreceiving data from said image-forming device in response to thetransmission-request signal transmitted to said image-forming device,and transmitting the data received from said image-forming device tosaid central management device; stopping the power supply from saidpower source to said communication-related part after completingtransmission of the data received from said image-forming device to saidcentral management device; supplying the electricity constantly from apower source of said image-forming device to signal receiving meansreceiving the transmission-request signal from said data communicationdevice; deciding a part that needs the power supply for acquiring thedata which should be transmitted to said central management device amongthe data related to said image-forming device, based on said informationadded to the transmission-request signal if the transmission-requestsignal is received by said signal receiving means; supplying theelectricity from the power source of said image-forming device to thepart that needs the power supply for acquiring the data which should betransmitted to said central management device, and a part that needs thepower supply for transmitting the data to said data communicationdevice; and stopping the power supply from the power source of saidimage-forming device to the part that needs the power supply foracquiring the data which should be transmitted to said centralmanagement device, and the part that needs the power supply fortransmitting the data to said data communication device, aftertransmitting the data to said data communication device.
 50. A method ofcontrolling power supply in an image-forming-device management systemthat manages an image-forming device by using a central managementdevice through a data communication device, said method comprising thesteps of: supplying electricity constantly from a power source of saiddata communication device to call-signal receiving means for receiving acall signal from a call origin, and call-origin deciding means fordeciding whether the call origin is said central management device whenreceiving the call signal by the call-signal receiving means, in saiddata communication device; supplying the electricity from the powersource of said data communication device to a communication-related partif deciding that the call origin is said central management device;transmitting a transmission request from said data communication deviceto said image forming device by use of said communication-related part;receiving data from said image-forming device in response to thetransmission request transmitted to said image-forming device;transmitting the data to said central management device; and stoppingsupplying the electricity from said power source to saidcommunication-related part after transmitting the data to said centralmanagement device.
 51. The method as claimed in claim 50, furthercomprising the steps of: supplying the electricity constantly from apower source of said image-forming device to request receiving meansreceiving the transmission request from said data communication device,in said image forming device; deciding a first part that needs the powersupply for acquiring the data, based on the transmission request if thetransmission-request signal is received by said signal receiving means;supplying the electricity from the power source of said image-formingdevice to the first part, and a second part that needs the power supplyfor transmitting the data to said data communication device;transmitting the data to said data communication device; and stoppingsupplying the electricity from the power source of said image-formingdevice to the first part and the second part after transmitting the datato said data communication device.